21772022400 has 864 divisors, whose sum is σ = 86817105180. Its totient is φ = 5374771200.

The previous prime is 21772022333. The next prime is 21772022407. The reversal of 21772022400 is 422027712.

21772022400 is a `hidden beast` number, since 217 + 7 + 20 + 22 + 400 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 4807480896 + 16964541504 = 69336^2 + 130248^2 .

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×21772022400² (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 not an unprimeable number, because it can be changed into a prime (21772022407) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 356918370 + ... + 356918430.

Almost surely, 2^21772022400 is an apocalyptic number.

21772022400 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 21772022400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43408552590).

21772022400 is an abundant number, since it is smaller than the sum of its proper divisors (65045082780).

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

21772022400 is an frugal number, since it uses more digits than its factorization.

21772022400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The spelling of 21772022400 in words is "twenty-one billion, seven hundred seventy-two million, twenty-two thousand, four hundred".