21255616145361 has 16 divisors (see below), whose sum is σ = 30599344601280. Its totient is φ = 13046753503680.

The previous prime is 21255616145299. The next prime is 21255616145461. The reversal of 21255616145361 is 16354161655212.

It is not a de Polignac number, because 21255616145361 - 2²⁶ = 21255549036497 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21255616145361.

It is not an unprimeable number, because it can be changed into a prime (21255616145461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 700519275 + ... + 700549616.

It is an arithmetic number, because the mean of its divisors is an integer number (1912459037580).

Almost surely, 2^{21255616145361} is an apocalyptic number.

It is an amenable number.

21255616145361 is a deficient number, since it is larger than the sum of its proper divisors (9343728455919).

21255616145361 is a wasteful number, since it uses less digits than its factorization.

21255616145361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1401069296.

The product of its digits is 1296000, while the sum is 48.

The spelling of 21255616145361 in words is "twenty-one trillion, two hundred fifty-five billion, six hundred sixteen million, one hundred forty-five thousand, three hundred sixty-one".