21269401200 has 360 divisors, whose sum is σ = 77191948288. Its totient is φ = 5623914240.

The previous prime is 21269401177. The next prime is 21269401229. The reversal of 21269401200 is 210496212.

It is a tau number, because it is divible by the number of its divisors (360).

It is a super-2 number, since 2×21269401200² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 12343539 + ... + 12345261.

Almost surely, 2^21269401200 is an apocalyptic number.

21269401200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21269401200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38595974144).

21269401200 is an abundant number, since it is smaller than the sum of its proper divisors (55922547088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21269401200 is a wasteful number, since it uses less digits than its factorization.

21269401200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1883 (or 1860 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

Adding to 21269401200 its reverse (210496212), we get a palindrome (21479897412).

The spelling of 21269401200 in words is "twenty-one billion, two hundred sixty-nine million, four hundred one thousand, two hundred".