639034439 has 2 divisors, whose sum is σ = 639034440. Its totient is φ = 639034438.

The previous prime is 639034433. The next prime is 639034447. The reversal of 639034439 is 934430936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639034439 - 2¹⁶ = 638968903 is a prime.

It is a super-3 number, since 3×639034439³ (a number of 27 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 639034396 and 639034405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639034433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319517219 + 319517220.

It is an arithmetic number, because the mean of its divisors is an integer number (319517220).

Almost surely, 2^639034439 is an apocalyptic number.

639034439 is a deficient number, since it is larger than the sum of its proper divisors (1).

639034439 is an equidigital number, since it uses as much as digits as its factorization.

639034439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 41.

The square root of 639034439 is about 25279.1305032432. The cubic root of 639034439 is about 861.3402749428.

The spelling of 639034439 in words is "six hundred thirty-nine million, thirty-four thousand, four hundred thirty-nine".