21237524406 has 64 divisors (see below), whose sum is σ = 53951592960. Its totient is φ = 6066174240.

The previous prime is 21237524393. The next prime is 21237524437. The reversal of 21237524406 is 60442573212.

21237524406 is a `hidden beast` number, since 2 + 123 + 7 + 524 + 4 + 0 + 6 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2104585 + ... + 2114651.

It is an arithmetic number, because the mean of its divisors is an integer number (842993640).

Almost surely, 2^21237524406 is an apocalyptic number.

21237524406 is an abundant number, since it is smaller than the sum of its proper divisors (32714068554).

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

21237524406 is a wasteful number, since it uses less digits than its factorization.

21237524406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15666 (or 15660 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 21237524406 in words is "twenty-one billion, two hundred thirty-seven million, five hundred twenty-four thousand, four hundred six".