21616535100 has 72 divisors (see below), whose sum is σ = 63163176048. Its totient is φ = 5707328000.

The previous prime is 21616535093. The next prime is 21616535159. The reversal of 21616535100 is 153561612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 326409 + ... + 387008.

It is an arithmetic number, because the mean of its divisors is an integer number (877266334).

Almost surely, 2^21616535100 is an apocalyptic number.

21616535100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21616535100 is an abundant number, since it is smaller than the sum of its proper divisors (41546640948).

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

21616535100 is a wasteful number, since it uses less digits than its factorization.

21616535100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713535 (or 713528 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The spelling of 21616535100 in words is "twenty-one billion, six hundred sixteen million, five hundred thirty-five thousand, one hundred".