| Base | Representation |
|---|---|
| bin | 10100011001111011… |
| … | …101101101010010000 |
| 3 | 2002112221101021111100 |
| 4 | 110121323231222100 |
| 5 | 324332414423100 |
| 6 | 14022033344400 |
| 7 | 1403643151644 |
| oct | 243173555220 |
| 9 | 62487337440 |
| 10 | 21909920400 |
| 11 | 9323640535 |
| 12 | 42b5708100 |
| 13 | 20b22a2a54 |
| 14 | 10bbc12c24 |
| 15 | 883788400 |
| hex | 519eeda90 |
21909920400 has 135 divisors (see below), whose sum is σ = 76064342601. Its totient is φ = 5840277120.
The previous prime is 21909920311. The next prime is 21909920429. The reversal of 21909920400 is 402990912.
The square root of 21909920400 is 148020.
It is a perfect power (a square), and thus also a powerful number.
It can be written as a sum of positive squares in only one way, i.e., 7887571344 + 14022349056 = 88812^2 + 118416^2 .
It is a super-2 number, since 2×219099204002 (a number of 21 digits) contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (36).
It is an unprimeable number.
It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8879967 + ... + 8882433.
Almost surely, 221909920400 is an apocalyptic number.
21909920400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
21909920400 is the 148020-th square number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 21909920400
21909920400 is an abundant number, since it is smaller than the sum of its proper divisors (54154422201).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21909920400 is an equidigital number, since it uses as much as digits as its factorization.
21909920400 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 4958 (or 2477 counting only the distinct ones).
The product of its (nonzero) digits is 11664, while the sum is 36.
Multiplying 21909920400 by its sum of digits (36), we get a square (788757134400 = 8881202).
21909920400 divided by its sum of digits (36) gives a square (608608900 = 246702).
Multiplying 21909920400 by its product of nonzero digits (11664), we get a square (255557311545600 = 159861602).
The spelling of 21909920400 in words is "twenty-one billion, nine hundred nine million, nine hundred twenty thousand, four hundred".
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.068 sec. • engine limits •