21204767615 has 16 divisors (see below), whose sum is σ = 26112391200. Its totient is φ = 16523974272.

The previous prime is 21204767569. The next prime is 21204767621. The reversal of 21204767615 is 51676740212.

It is a cyclic number.

It is not a de Polignac number, because 21204767615 - 2²⁴ = 21187990399 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 251000 + ... + 324669.

It is an arithmetic number, because the mean of its divisors is an integer number (1632024450).

Almost surely, 2^21204767615 is an apocalyptic number.

21204767615 is a deficient number, since it is larger than the sum of its proper divisors (4907623585).

21204767615 is a wasteful number, since it uses less digits than its factorization.

21204767615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575866.

The product of its (nonzero) digits is 141120, while the sum is 41.

The spelling of 21204767615 in words is "twenty-one billion, two hundred four million, seven hundred sixty-seven thousand, six hundred fifteen".