639565051 has 2 divisors, whose sum is σ = 639565052. Its totient is φ = 639565050.

The previous prime is 639564983. The next prime is 639565057. The reversal of 639565051 is 150565936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639565051 - 2⁷ = 639564923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 639564995 and 639565013.

It is not a weakly prime, because it can be changed into another prime (639565057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319782525 + 319782526.

It is an arithmetic number, because the mean of its divisors is an integer number (319782526).

Almost surely, 2^639565051 is an apocalyptic number.

639565051 is a deficient number, since it is larger than the sum of its proper divisors (1).

639565051 is an equidigital number, since it uses as much as digits as its factorization.

639565051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 121500, while the sum is 40.

The square root of 639565051 is about 25289.6233858869. The cubic root of 639565051 is about 861.5786090182.

The spelling of 639565051 in words is "six hundred thirty-nine million, five hundred sixty-five thousand, fifty-one".