21631617400 has 24 divisors (see below), whose sum is σ = 50293510920. Its totient is φ = 8652646880.

The previous prime is 21631617311. The next prime is 21631617431. The reversal of 21631617400 is 471613612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54078844 + ... + 54079243.

It is an arithmetic number, because the mean of its divisors is an integer number (2095562955).

Almost surely, 2^21631617400 is an apocalyptic number.

21631617400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21631617400 is an abundant number, since it is smaller than the sum of its proper divisors (28661893520).

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

21631617400 is a wasteful number, since it uses less digits than its factorization.

21631617400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108158103 (or 108158094 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The spelling of 21631617400 in words is "twenty-one billion, six hundred thirty-one million, six hundred seventeen thousand, four hundred".