21145684265 has 16 divisors (see below), whose sum is σ = 25650535680. Its totient is φ = 16732930560.

The previous prime is 21145684249. The next prime is 21145684279. The reversal of 21145684265 is 56248654112.

It is not a de Polignac number, because 21145684265 - 2⁴ = 21145684249 is a prime.

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, 948800 + ... + 970830.

It is an arithmetic number, because the mean of its divisors is an integer number (1603158480).

Almost surely, 2^21145684265 is an apocalyptic number.

It is an amenable number.

21145684265 is a deficient number, since it is larger than the sum of its proper divisors (4504851415).

21145684265 is a wasteful number, since it uses less digits than its factorization.

21145684265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24112.

The product of its digits is 460800, while the sum is 44.

The spelling of 21145684265 in words is "twenty-one billion, one hundred forty-five million, six hundred eighty-four thousand, two hundred sixty-five".