117889991 has 2 divisors, whose sum is σ = 117889992. Its totient is φ = 117889990.

The previous prime is 117889979. The next prime is 117890039. The reversal of 117889991 is 199988711.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 117889991 - 2²⁶ = 50781127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117889691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58944995 + 58944996.

It is an arithmetic number, because the mean of its divisors is an integer number (58944996).

Almost surely, 2^117889991 is an apocalyptic number.

117889991 is a deficient number, since it is larger than the sum of its proper divisors (1).

117889991 is an equidigital number, since it uses as much as digits as its factorization.

117889991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 53.

The square root of 117889991 is about 10857.7157358258. The cubic root of 117889991 is about 490.3343421341.

The spelling of 117889991 in words is "one hundred seventeen million, eight hundred eighty-nine thousand, nine hundred ninety-one".