639577 has 2 divisors, whose sum is σ = 639578. Its totient is φ = 639576.

The previous prime is 639571. The next prime is 639589. The reversal of 639577 is 775936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 373321 + 266256 = 611^2 + 516^2 .

It is a cyclic number.

It is not a de Polignac number, because 639577 - 2¹¹ = 637529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (639571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319788 + 319789.

It is an arithmetic number, because the mean of its divisors is an integer number (319789).

2⁶³⁹⁵⁷⁷ is an apocalyptic number.

It is an amenable number.

639577 is a deficient number, since it is larger than the sum of its proper divisors (1).

639577 is an equidigital number, since it uses as much as digits as its factorization.

639577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39690, while the sum is 37.

The square root of 639577 is about 799.7355813017. The cubic root of 639577 is about 86.1583974612.

It can be divided in two parts, 63 and 9577, that multiplied together give a triangular number (603351 = T₁₀₉₈).

The spelling of 639577 in words is "six hundred thirty-nine thousand, five hundred seventy-seven".