21007971024 has 40 divisors (see below), whose sum is σ = 54750876672. Its totient is φ = 6940684800.

The previous prime is 21007971001. The next prime is 21007971043. The reversal of 21007971024 is 42017970012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1931152 + ... + 1941999.

Almost surely, 2^21007971024 is an apocalyptic number.

21007971024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21007971024 is an abundant number, since it is smaller than the sum of its proper divisors (33742905648).

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

21007971024 is a wasteful number, since it uses less digits than its factorization.

21007971024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3873275 (or 3873269 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 33.

The spelling of 21007971024 in words is "twenty-one billion, seven million, nine hundred seventy-one thousand, twenty-four".