21651625015 has 32 divisors (see below), whose sum is σ = 27035068032. Its totient is φ = 16633344000.

The previous prime is 21651625007. The next prime is 21651625033. The reversal of 21651625015 is 51052615612.

It is not a de Polignac number, because 21651625015 - 2³ = 21651625007 is a prime.

It is a Duffinian 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, 15907935 + ... + 15909295.

It is an arithmetic number, because the mean of its divisors is an integer number (844845876).

Almost surely, 2^21651625015 is an apocalyptic number.

21651625015 is a deficient number, since it is larger than the sum of its proper divisors (5383443017).

21651625015 is a wasteful number, since it uses less digits than its factorization.

21651625015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2571.

The product of its (nonzero) digits is 18000, while the sum is 34.

The spelling of 21651625015 in words is "twenty-one billion, six hundred fifty-one million, six hundred twenty-five thousand, fifteen".