21531042524 has 12 divisors (see below), whose sum is σ = 38195480064. Its totient is φ = 10618048224.

The previous prime is 21531042437. The next prime is 21531042527. The reversal of 21531042524 is 42524013512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531042527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36867932 + ... + 36868515.

It is an arithmetic number, because the mean of its divisors is an integer number (3182956672).

Almost surely, 2^21531042524 is an apocalyptic number.

It is an amenable number.

21531042524 is a deficient number, since it is larger than the sum of its proper divisors (16664437540).

21531042524 is a wasteful number, since it uses less digits than its factorization.

21531042524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73736524 (or 73736522 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The spelling of 21531042524 in words is "twenty-one billion, five hundred thirty-one million, forty-two thousand, five hundred twenty-four".