639823523 has 2 divisors, whose sum is σ = 639823524. Its totient is φ = 639823522.

The previous prime is 639823489. The next prime is 639823603. The reversal of 639823523 is 325328936.

639823523 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639823523 - 2¹⁴ = 639807139 is a prime.

It is not a weakly prime, because it can be changed into another prime (639823123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319911761 + 319911762.

It is an arithmetic number, because the mean of its divisors is an integer number (319911762).

Almost surely, 2^639823523 is an apocalyptic number.

639823523 is a deficient number, since it is larger than the sum of its proper divisors (1).

639823523 is an equidigital number, since it uses as much as digits as its factorization.

639823523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 41.

The square root of 639823523 is about 25294.7331079021. The cubic root of 639823523 is about 861.6946586955.

The spelling of 639823523 in words is "six hundred thirty-nine million, eight hundred twenty-three thousand, five hundred twenty-three".