638965258 has 16 divisors (see below), whose sum is σ = 967230720. Its totient is φ = 316566000.

The previous prime is 638965253. The next prime is 638965267. The reversal of 638965258 is 852569836.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (638965253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 127708 + ... + 132616.

It is an arithmetic number, because the mean of its divisors is an integer number (60451920).

Almost surely, 2^638965258 is an apocalyptic number.

638965258 is a deficient number, since it is larger than the sum of its proper divisors (328265462).

638965258 is a wasteful number, since it uses less digits than its factorization.

638965258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5493.

The product of its digits is 3110400, while the sum is 52.

The square root of 638965258 is about 25277.7621240489. The cubic root of 638965258 is about 861.3091913119.

The spelling of 638965258 in words is "six hundred thirty-eight million, nine hundred sixty-five thousand, two hundred fifty-eight".