18979817090 has 32 divisors (see below), whose sum is σ = 37009390320. Its totient is φ = 7007924352.

The previous prime is 18979817039. The next prime is 18979817099. The reversal of 18979817090 is 9071897981.

It can be written as a sum of positive squares in 8 ways, for example, as 310147321 + 18669669769 = 17611^2 + 136637^2 .

It is not an unprimeable number, because it can be changed into a prime (18979817099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 409979 + ... + 453918.

Almost surely, 2^18979817090 is an apocalyptic number.

18979817090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18979817090 is a deficient number, since it is larger than the sum of its proper divisors (18029573230).

18979817090 is an equidigital number, since it uses as much as digits as its factorization.

18979817090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 863943 (or 863917 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 59.

The spelling of 18979817090 in words is "eighteen billion, nine hundred seventy-nine million, eight hundred seventeen thousand, ninety".