168870391 has 2 divisors, whose sum is σ = 168870392. Its totient is φ = 168870390.

The previous prime is 168870379. The next prime is 168870407. The reversal of 168870391 is 193078861.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 168870391 - 2²¹ = 166773239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168870311) 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 as a sum of consecutive naturals, namely, 84435195 + 84435196.

It is an arithmetic number, because the mean of its divisors is an integer number (84435196).

Almost surely, 2^168870391 is an apocalyptic number.

168870391 is a deficient number, since it is larger than the sum of its proper divisors (1).

168870391 is an equidigital number, since it uses as much as digits as its factorization.

168870391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 168870391 is about 12995.0140823317. The cubic root of 168870391 is about 552.7361081453.

The spelling of 168870391 in words is "one hundred sixty-eight million, eight hundred seventy thousand, three hundred ninety-one".