18456785657 has 2 divisors, whose sum is σ = 18456785658. Its totient is φ = 18456785656.

The previous prime is 18456785653. The next prime is 18456785701. The reversal of 18456785657 is 75658765481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18449517241 + 7268416 = 135829^2 + 2696^2 .

It is a cyclic number.

It is not a de Polignac number, because 18456785657 - 2² = 18456785653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18456785657.

It is not a weakly prime, because it can be changed into another prime (18456785651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9228392828 + 9228392829.

It is an arithmetic number, because the mean of its divisors is an integer number (9228392829).

Almost surely, 2^18456785657 is an apocalyptic number.

It is an amenable number.

18456785657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18456785657 is an equidigital number, since it uses as much as digits as its factorization.

18456785657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448000, while the sum is 62.

The spelling of 18456785657 in words is "eighteen billion, four hundred fifty-six million, seven hundred eighty-five thousand, six hundred fifty-seven".