638959 has 2 divisors, whose sum is σ = 638960. Its totient is φ = 638958.

The previous prime is 638933. The next prime is 638971. The reversal of 638959 is 959836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638959 - 2¹⁹ = 114671 is a prime.

It is a Chen prime.

It is a plaindrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319479 + 319480.

It is an arithmetic number, because the mean of its divisors is an integer number (319480).

2⁶³⁸⁹⁵⁹ is an apocalyptic number.

638959 is a deficient number, since it is larger than the sum of its proper divisors (1).

638959 is an equidigital number, since it uses as much as digits as its factorization.

638959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 40.

The square root of 638959 is about 799.3491102141. The cubic root of 638959 is about 86.1306379427.

The spelling of 638959 in words is "six hundred thirty-eight thousand, nine hundred fifty-nine".