20736904957 has 2 divisors, whose sum is σ = 20736904958. Its totient is φ = 20736904956.

The previous prime is 20736904939. The next prime is 20736904973. The reversal of 20736904957 is 75940963702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15012620676 + 5724284281 = 122526^2 + 75659^2 .

It is a cyclic number.

It is not a de Polignac number, because 20736904957 - 2²³ = 20728516349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20736934957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10368452478 + 10368452479.

It is an arithmetic number, because the mean of its divisors is an integer number (10368452479).

Almost surely, 2^20736904957 is an apocalyptic number.

It is an amenable number.

20736904957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20736904957 is an equidigital number, since it uses as much as digits as its factorization.

20736904957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2857680, while the sum is 52.

The spelling of 20736904957 in words is "twenty billion, seven hundred thirty-six million, nine hundred four thousand, nine hundred fifty-seven".