21356652600 has 72 divisors (see below), whose sum is σ = 71722764360. Its totient is φ = 5695106880.

The previous prime is 21356652589. The next prime is 21356652601. The reversal of 21356652600 is 625665312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21356652600² (a number of 21 digits) contains 22 as substring.

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 (21356652601) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 5930604 + ... + 5934203.

It is an arithmetic number, because the mean of its divisors is an integer number (996149505).

Almost surely, 2^21356652600 is an apocalyptic number.

21356652600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21356652600 is an abundant number, since it is smaller than the sum of its proper divisors (50366111760).

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

21356652600 is a wasteful number, since it uses less digits than its factorization.

21356652600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11864829 (or 11864817 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21356652600 in words is "twenty-one billion, three hundred fifty-six million, six hundred fifty-two thousand, six hundred".