117906391 has 2 divisors, whose sum is σ = 117906392. Its totient is φ = 117906390.

The previous prime is 117906389. The next prime is 117906413. The reversal of 117906391 is 193609711.

It is a weak prime.

It is an emirp because it is prime and its reverse (193609711) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 117906391 - 2¹ = 117906389 is a prime.

Together with 117906389, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 117906391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117906791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58953195 + 58953196.

It is an arithmetic number, because the mean of its divisors is an integer number (58953196).

Almost surely, 2^117906391 is an apocalyptic number.

117906391 is the 6868-th centered pentagonal number.

117906391 is a deficient number, since it is larger than the sum of its proper divisors (1).

117906391 is an equidigital number, since it uses as much as digits as its factorization.

117906391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 117906391 is about 10858.4709328708. The cubic root of 117906391 is about 490.3570783316.

It can be divided in two parts, 11790 and 6391, that added together give a palindrome (18181).

The spelling of 117906391 in words is "one hundred seventeen million, nine hundred six thousand, three hundred ninety-one".