21955622400 has 960 divisors, whose sum is σ = 88502103360. Its totient is φ = 5308416000.

The previous prime is 21955622399. The next prime is 21955622407. The reversal of 21955622400 is 422655912.

21955622400 is a `hidden beast` number, since 2 + 1 + 95 + 562 + 2 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21955622407) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 217382350 + ... + 217382450.

It is an arithmetic number, because the mean of its divisors is an integer number (92189691).

Almost surely, 2^21955622400 is an apocalyptic number.

21955622400 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 21955622400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44251051680).

21955622400 is an abundant number, since it is smaller than the sum of its proper divisors (66546480960).

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

21955622400 is a wasteful number, since it uses less digits than its factorization.

21955622400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 21955622400 in words is "twenty-one billion, nine hundred fifty-five million, six hundred twenty-two thousand, four hundred".