21015582402 has 16 divisors (see below), whose sum is σ = 43858607040. Its totient is φ = 6700620432.

The previous prime is 21015582353. The next prime is 21015582409. The reversal of 21015582402 is 20428551012.

It is a self number, because there is not a number n which added to its sum of digits gives 21015582402.

It is not an unprimeable number, because it can be changed into a prime (21015582409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76143277 + ... + 76143552.

It is an arithmetic number, because the mean of its divisors is an integer number (2741162940).

Almost surely, 2^21015582402 is an apocalyptic number.

21015582402 is an abundant number, since it is smaller than the sum of its proper divisors (22843024638).

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

21015582402 is a wasteful number, since it uses less digits than its factorization.

21015582402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152286857.

The product of its (nonzero) digits is 6400, while the sum is 30.

The spelling of 21015582402 in words is "twenty-one billion, fifteen million, five hundred eighty-two thousand, four hundred two".