18168787457 has 2 divisors, whose sum is σ = 18168787458. Its totient is φ = 18168787456.

The previous prime is 18168787423. The next prime is 18168787499. The reversal of 18168787457 is 75478786181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17171743681 + 997043776 = 131041^2 + 31576^2 .

It is a cyclic number.

It is not a de Polignac number, because 18168787457 - 2²⁰ = 18167738881 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18168787457.

It is not a weakly prime, because it can be changed into another prime (18168787057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9084393728 + 9084393729.

It is an arithmetic number, because the mean of its divisors is an integer number (9084393729).

Almost surely, 2^18168787457 is an apocalyptic number.

It is an amenable number.

18168787457 is a deficient number, since it is larger than the sum of its proper divisors (1).

18168787457 is an equidigital number, since it uses as much as digits as its factorization.

18168787457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21073920, while the sum is 62.

The spelling of 18168787457 in words is "eighteen billion, one hundred sixty-eight million, seven hundred eighty-seven thousand, four hundred fifty-seven".