21315605502 has 16 divisors (see below), whose sum is σ = 43783406352. Its totient is φ = 6913169280.

The previous prime is 21315605413. The next prime is 21315605527. The reversal of 21315605502 is 20550651312.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21315605502.

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, 48007899 + ... + 48008342.

It is an arithmetic number, because the mean of its divisors is an integer number (2736462897).

Almost surely, 2^21315605502 is an apocalyptic number.

21315605502 is an abundant number, since it is smaller than the sum of its proper divisors (22467800850).

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

21315605502 is a wasteful number, since it uses less digits than its factorization.

21315605502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96016283.

The product of its (nonzero) digits is 9000, while the sum is 30.

The spelling of 21315605502 in words is "twenty-one billion, three hundred fifteen million, six hundred five thousand, five hundred two".