18716638937 has 6 divisors (see below), whose sum is σ = 19818214974. Its totient is φ = 17615129280.

The previous prime is 18716638933. The next prime is 18716638961. The reversal of 18716638937 is 73983661781.

It can be written as a sum of positive squares in 3 ways, for example, as 3946854976 + 14769783961 = 62824^2 + 121531^2 .

It is not a de Polignac number, because 18716638937 - 2² = 18716638933 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18716638931) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 547487 + ... + 580667.

It is an arithmetic number, because the mean of its divisors is an integer number (3303035829).

Almost surely, 2^18716638937 is an apocalyptic number.

18716638937 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18716638937 is a deficient number, since it is larger than the sum of its proper divisors (1101576037).

18716638937 is an frugal number, since it uses more digits than its factorization.

18716638937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66379 (or 33198 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 59.

The spelling of 18716638937 in words is "eighteen billion, seven hundred sixteen million, six hundred thirty-eight thousand, nine hundred thirty-seven".