20294731657 has 16 divisors (see below), whose sum is σ = 21572197200. Its totient is φ = 19056280320.

The previous prime is 20294731621. The next prime is 20294731673. The reversal of 20294731657 is 75613749202.

It can be written as a sum of positive squares in 8 ways, for example, as 3864362896 + 16430368761 = 62164^2 + 128181^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20294731657 is a prime.

It is a super-2 number, since 2×20294731657² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20294731057) 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, 3633607 + ... + 3639187.

It is an arithmetic number, because the mean of its divisors is an integer number (1348262325).

Almost surely, 2^20294731657 is an apocalyptic number.

It is an amenable number.

20294731657 is a deficient number, since it is larger than the sum of its proper divisors (1277465543).

20294731657 is a wasteful number, since it uses less digits than its factorization.

20294731657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9036.

The product of its (nonzero) digits is 635040, while the sum is 46.

The spelling of 20294731657 in words is "twenty billion, two hundred ninety-four million, seven hundred thirty-one thousand, six hundred fifty-seven".