21531513024 has 84 divisors (see below), whose sum is σ = 70532806864. Its totient is φ = 6151859712.

The previous prime is 21531513011. The next prime is 21531513061. The reversal of 21531513024 is 42031513512.

21531513024 is a `hidden beast` number, since 215 + 315 + 130 + 2 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (84).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2666047 + ... + 2674110.

Almost surely, 2^21531513024 is an apocalyptic number.

21531513024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21531513024 is an abundant number, since it is smaller than the sum of its proper divisors (49001293840).

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

21531513024 is a wasteful number, since it uses less digits than its factorization.

21531513024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5340182 (or 5340169 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 21531513024 in words is "twenty-one billion, five hundred thirty-one million, five hundred thirteen thousand, twenty-four".