639137 has 2 divisors, whose sum is σ = 639138. Its totient is φ = 639136.

The previous prime is 639091. The next prime is 639143. The reversal of 639137 is 731936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 625681 + 13456 = 791^2 + 116^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639137 is a prime.

It is a super-2 number, since 2×639137² = 816992209538, which contains 22 as substring.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639137.

It is not a weakly prime, because it can be changed into another prime (639157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319568 + 319569.

It is an arithmetic number, because the mean of its divisors is an integer number (319569).

2⁶³⁹¹³⁷ is an apocalyptic number.

It is an amenable number.

639137 is a deficient number, since it is larger than the sum of its proper divisors (1).

639137 is an equidigital number, since it uses as much as digits as its factorization.

639137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 29.

The square root of 639137 is about 799.4604430489. The cubic root of 639137 is about 86.1386352373.

The spelling of 639137 in words is "six hundred thirty-nine thousand, one hundred thirty-seven".