18506951657 has 2 divisors, whose sum is σ = 18506951658. Its totient is φ = 18506951656.

The previous prime is 18506951563. The next prime is 18506951693. The reversal of 18506951657 is 75615960581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18042936976 + 464014681 = 134324^2 + 21541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18506951657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18506951599 and 18506951608.

It is not a weakly prime, because it can be changed into another prime (18506951557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9253475828 + 9253475829.

It is an arithmetic number, because the mean of its divisors is an integer number (9253475829).

Almost surely, 2^18506951657 is an apocalyptic number.

It is an amenable number.

18506951657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18506951657 is an equidigital number, since it uses as much as digits as its factorization.

18506951657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268000, while the sum is 53.

The spelling of 18506951657 in words is "eighteen billion, five hundred six million, nine hundred fifty-one thousand, six hundred fifty-seven".