18368991057 has 16 divisors (see below), whose sum is σ = 26031349760. Its totient is φ = 11488828752.

The previous prime is 18368991041. The next prime is 18368991071. The reversal of 18368991057 is 75019986381.

It is not a de Polignac number, because 18368991057 - 2⁴ = 18368991041 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a junction number, because it is equal to n+sod(n) for n = 18368990988 and 18368991006.

It is not an unprimeable number, because it can be changed into a prime (18368991097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1558513 + ... + 1570254.

It is an arithmetic number, because the mean of its divisors is an integer number (1626959360).

Almost surely, 2^18368991057 is an apocalyptic number.

It is an amenable number.

18368991057 is a deficient number, since it is larger than the sum of its proper divisors (7662358703).

18368991057 is a wasteful number, since it uses less digits than its factorization.

18368991057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3128892.

The product of its (nonzero) digits is 3265920, while the sum is 57.

The spelling of 18368991057 in words is "eighteen billion, three hundred sixty-eight million, nine hundred ninety-one thousand, fifty-seven".