18930638117 has 2 divisors, whose sum is σ = 18930638118. Its totient is φ = 18930638116.

The previous prime is 18930638101. The next prime is 18930638137. The reversal of 18930638117 is 71183603981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17242578721 + 1688059396 = 131311^2 + 41086^2 .

It is a cyclic number.

It is not a de Polignac number, because 18930638117 - 2⁴ = 18930638101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18930638137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9465319058 + 9465319059.

It is an arithmetic number, because the mean of its divisors is an integer number (9465319059).

Almost surely, 2^18930638117 is an apocalyptic number.

It is an amenable number.

18930638117 is a deficient number, since it is larger than the sum of its proper divisors (1).

18930638117 is an equidigital number, since it uses as much as digits as its factorization.

18930638117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 47.

The spelling of 18930638117 in words is "eighteen billion, nine hundred thirty million, six hundred thirty-eight thousand, one hundred seventeen".