21037660544 has 16 divisors (see below), whose sum is σ = 41910964620. Its totient is φ = 10518830208.

The previous prime is 21037660543. The next prime is 21037660547. The reversal of 21037660544 is 44506673012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×21037660544² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21037660498 and 21037660507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21037660543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82178234 + ... + 82178489.

Almost surely, 2^21037660544 is an apocalyptic number.

It is an amenable number.

21037660544 is a deficient number, since it is larger than the sum of its proper divisors (20873304076).

21037660544 is an equidigital number, since it uses as much as digits as its factorization.

21037660544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164356737 (or 164356725 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 38.

The spelling of 21037660544 in words is "twenty-one billion, thirty-seven million, six hundred sixty thousand, five hundred forty-four".