649868939 has 2 divisors, whose sum is σ = 649868940. Its totient is φ = 649868938.

The previous prime is 649868909. The next prime is 649868941. The reversal of 649868939 is 939868946.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 649868939 - 2²⁸ = 381433483 is a prime.

Together with 649868941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (649868909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324934469 + 324934470.

It is an arithmetic number, because the mean of its divisors is an integer number (324934470).

Almost surely, 2^649868939 is an apocalyptic number.

649868939 is a deficient number, since it is larger than the sum of its proper divisors (1).

649868939 is an equidigital number, since it uses as much as digits as its factorization.

649868939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20155392, while the sum is 62.

The square root of 649868939 is about 25492.5271207074. The cubic root of 649868939 is about 866.1808808308.

The spelling of 649868939 in words is "six hundred forty-nine million, eight hundred sixty-eight thousand, nine hundred thirty-nine".