21125636531215 has 8 divisors (see below), whose sum is σ = 25483490350848. Its totient is φ = 16812024882720.

The previous prime is 21125636531201. The next prime is 21125636531269. The reversal of 21125636531215 is 51213563652112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21125636531215 - 2⁵ = 21125636531183 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 7 ways as a sum of consecutive naturals, for example, 11060541732 + ... + 11060543641.

It is an arithmetic number, because the mean of its divisors is an integer number (3185436293856).

Almost surely, 2^{21125636531215} is an apocalyptic number.

21125636531215 is a deficient number, since it is larger than the sum of its proper divisors (4357853819633).

21125636531215 is a wasteful number, since it uses less digits than its factorization.

21125636531215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22121085569.

The product of its digits is 324000, while the sum is 43.

The spelling of 21125636531215 in words is "twenty-one trillion, one hundred twenty-five billion, six hundred thirty-six million, five hundred thirty-one thousand, two hundred fifteen".