21010631808 has 32 divisors (see below), whose sum is σ = 55809491760. Its totient is φ = 7003543808.

The previous prime is 21010631801. The next prime is 21010631819. The reversal of 21010631808 is 80813601012.

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (21010631801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27357210 + ... + 27357977.

Almost surely, 2^21010631808 is an apocalyptic number.

It is an amenable number.

21010631808 is an abundant number, since it is smaller than the sum of its proper divisors (34798859952).

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

21010631808 is an equidigital number, since it uses as much as digits as its factorization.

21010631808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54715204 (or 54715192 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The spelling of 21010631808 in words is "twenty-one billion, ten million, six hundred thirty-one thousand, eight hundred eight".