21365506620613 has 8 divisors (see below), whose sum is σ = 21862459697408. Its totient is φ = 20868557217984.

The previous prime is 21365506620587. The next prime is 21365506620637. The reversal of 21365506620613 is 31602660556312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365506620613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365506620643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13419820 + ... + 14927242.

It is an arithmetic number, because the mean of its divisors is an integer number (2732807462176).

Almost surely, 2^{21365506620613} is an apocalyptic number.

It is an amenable number.

21365506620613 is a deficient number, since it is larger than the sum of its proper divisors (496953076795).

21365506620613 is a wasteful number, since it uses less digits than its factorization.

21365506620613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1837083.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The spelling of 21365506620613 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred six million, six hundred twenty thousand, six hundred thirteen".