20979911802157 has 16 divisors (see below), whose sum is σ = 26158255228800. Its totient is φ = 16347056927040.

The previous prime is 20979911802151. The next prime is 20979911802163. The reversal of 20979911802157 is 75120811997902.

It is an interprime number because it is at equal distance from previous prime (20979911802151) and next prime (20979911802163).

It is not a de Polignac number, because 20979911802157 - 2²⁷ = 20979777584429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20979911802095 and 20979911802104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979911802151) 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, 6349782 + ... + 9070807.

It is an arithmetic number, because the mean of its divisors is an integer number (1634890951800).

Almost surely, 2^{20979911802157} is an apocalyptic number.

It is an amenable number.

20979911802157 is a deficient number, since it is larger than the sum of its proper divisors (5178343426643).

20979911802157 is a wasteful number, since it uses less digits than its factorization.

20979911802157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15438276.

The product of its (nonzero) digits is 5715360, while the sum is 61.

The spelling of 20979911802157 in words is "twenty trillion, nine hundred seventy-nine billion, nine hundred eleven million, eight hundred two thousand, one hundred fifty-seven".