18086215657 has 2 divisors, whose sum is σ = 18086215658. Its totient is φ = 18086215656.

The previous prime is 18086215649. The next prime is 18086215751. The reversal of 18086215657 is 75651268081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13025885161 + 5060330496 = 114131^2 + 71136^2 .

It is a cyclic number.

It is not a de Polignac number, because 18086215657 - 2³ = 18086215649 is a prime.

It is a super-2 number, since 2×18086215657² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18086215657.

It is not a weakly prime, because it can be changed into another prime (18086215157) 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, 9043107828 + 9043107829.

It is an arithmetic number, because the mean of its divisors is an integer number (9043107829).

Almost surely, 2^18086215657 is an apocalyptic number.

It is an amenable number.

18086215657 is a deficient number, since it is larger than the sum of its proper divisors (1).

18086215657 is an equidigital number, since it uses as much as digits as its factorization.

18086215657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 806400, while the sum is 49.

The spelling of 18086215657 in words is "eighteen billion, eighty-six million, two hundred fifteen thousand, six hundred fifty-seven".