20615566131 has 24 divisors (see below), whose sum is σ = 30634718400. Its totient is φ = 13349581056.

The previous prime is 20615566109. The next prime is 20615566151. The reversal of 20615566131 is 13166551602.

20615566131 is a `hidden beast` number, since 2 + 0 + 61 + 5 + 566 + 1 + 31 = 666.

It is not a de Polignac number, because 20615566131 - 2¹¹ = 20615564083 is a prime.

It is a super-2 number, since 2×20615566131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20615566151) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145270 + ... + 249668.

It is an arithmetic number, because the mean of its divisors is an integer number (1276446600).

Almost surely, 2^20615566131 is an apocalyptic number.

20615566131 is a deficient number, since it is larger than the sum of its proper divisors (10019152269).

20615566131 is a wasteful number, since it uses less digits than its factorization.

20615566131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105035 (or 105032 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 20615566131 in words is "twenty billion, six hundred fifteen million, five hundred sixty-six thousand, one hundred thirty-one".