638925983 has 2 divisors, whose sum is σ = 638925984. Its totient is φ = 638925982.

The previous prime is 638925967. The next prime is 638926007. The reversal of 638925983 is 389529836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638925983 - 2⁴ = 638925967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638925913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319462991 + 319462992.

It is an arithmetic number, because the mean of its divisors is an integer number (319462992).

Almost surely, 2^638925983 is an apocalyptic number.

638925983 is a deficient number, since it is larger than the sum of its proper divisors (1).

638925983 is an equidigital number, since it uses as much as digits as its factorization.

638925983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2799360, while the sum is 53.

The square root of 638925983 is about 25276.9852434977. The cubic root of 638925983 is about 861.2915437110.

The spelling of 638925983 in words is "six hundred thirty-eight million, nine hundred twenty-five thousand, nine hundred eighty-three".