79515171701021 has 16 divisors (see below), whose sum is σ = 94009184755200. Its totient is φ = 65804889349248.

The previous prime is 79515171700933. The next prime is 79515171701039. The reversal of 79515171701021 is 12010717151597.

It is a de Polignac number, because none of the positive numbers 2^k-79515171701021 is a prime.

It is a super-2 number, since 2×79515171701021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79515171701071) 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, 15437081 + ... + 19933233.

It is an arithmetic number, because the mean of its divisors is an integer number (5875574047200).

Almost surely, 2^{79515171701021} is an apocalyptic number.

It is an amenable number.

79515171701021 is a deficient number, since it is larger than the sum of its proper divisors (14494013054179).

79515171701021 is a wasteful number, since it uses less digits than its factorization.

79515171701021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4583308.

The product of its (nonzero) digits is 154350, while the sum is 47.

The spelling of 79515171701021 in words is "seventy-nine trillion, five hundred fifteen billion, one hundred seventy-one million, seven hundred one thousand, twenty-one".