840166939 has 2 divisors, whose sum is σ = 840166940. Its totient is φ = 840166938.

The previous prime is 840166907. The next prime is 840166961. The reversal of 840166939 is 939661048.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 840166939 - 2⁵ = 840166907 is a prime.

It is not a weakly prime, because it can be changed into another prime (840166139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420083469 + 420083470.

It is an arithmetic number, because the mean of its divisors is an integer number (420083470).

Almost surely, 2^840166939 is an apocalyptic number.

840166939 is a deficient number, since it is larger than the sum of its proper divisors (1).

840166939 is an equidigital number, since it uses as much as digits as its factorization.

840166939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 840166939 is about 28985.6333206642. The cubic root of 840166939 is about 943.6012972497.

The spelling of 840166939 in words is "eight hundred forty million, one hundred sixty-six thousand, nine hundred thirty-nine".