639938527 has 2 divisors, whose sum is σ = 639938528. Its totient is φ = 639938526.

The previous prime is 639938501. The next prime is 639938539. The reversal of 639938527 is 725839936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639938527 - 2¹⁵ = 639905759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639938567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319969263 + 319969264.

It is an arithmetic number, because the mean of its divisors is an integer number (319969264).

Almost surely, 2^639938527 is an apocalyptic number.

639938527 is a deficient number, since it is larger than the sum of its proper divisors (1).

639938527 is an equidigital number, since it uses as much as digits as its factorization.

639938527 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2449440, while the sum is 52.

The square root of 639938527 is about 25297.0062853295. The cubic root of 639938527 is about 861.7462835535.

The spelling of 639938527 in words is "six hundred thirty-nine million, nine hundred thirty-eight thousand, five hundred twenty-seven".