639361 has 2 divisors, whose sum is σ = 639362. Its totient is φ = 639360.

The previous prime is 639337. The next prime is 639371. The reversal of 639361 is 163936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 442225 + 197136 = 665^2 + 444^2 .

It is a cyclic number.

It is not a de Polignac number, because 639361 - 2⁵ = 639329 is a prime.

It is not a weakly prime, because it can be changed into another prime (639311) 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, 319680 + 319681.

It is an arithmetic number, because the mean of its divisors is an integer number (319681).

2⁶³⁹³⁶¹ is an apocalyptic number.

It is an amenable number.

639361 is a deficient number, since it is larger than the sum of its proper divisors (1).

639361 is an equidigital number, since it uses as much as digits as its factorization.

639361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 28.

The square root of 639361 is about 799.6005252625. The cubic root of 639361 is about 86.1486971388.

It can be divided in two parts, 639 and 361, that added together give a cube (1000 = 10³).

The spelling of 639361 in words is "six hundred thirty-nine thousand, three hundred sixty-one".