168920639 has 2 divisors, whose sum is σ = 168920640. Its totient is φ = 168920638.

The previous prime is 168920627. The next prime is 168920663. The reversal of 168920639 is 936029861.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 168920639 - 2⁴ = 168920623 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168920639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168920669) 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, 84460319 + 84460320.

It is an arithmetic number, because the mean of its divisors is an integer number (84460320).

Almost surely, 2^168920639 is an apocalyptic number.

168920639 is a deficient number, since it is larger than the sum of its proper divisors (1).

168920639 is an equidigital number, since it uses as much as digits as its factorization.

168920639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 168920639 is about 12996.9472954229. The cubic root of 168920639 is about 552.7909255894.

The spelling of 168920639 in words is "one hundred sixty-eight million, nine hundred twenty thousand, six hundred thirty-nine".