638974810 has 8 divisors (see below), whose sum is σ = 1150154676. Its totient is φ = 255589920.

The previous prime is 638974781. The next prime is 638974813. The reversal of 638974810 is 18479836.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 543775761 + 95199049 = 23319^2 + 9757^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×638974810² = 816577615629072200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638974813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31948731 + ... + 31948750.

Almost surely, 2^638974810 is an apocalyptic number.

638974810 is a deficient number, since it is larger than the sum of its proper divisors (511179866).

638974810 is a wasteful number, since it uses less digits than its factorization.

638974810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63897488.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 638974810 is about 25277.9510641191. The cubic root of 638974810 is about 861.3134832429.

The spelling of 638974810 in words is "six hundred thirty-eight million, nine hundred seventy-four thousand, eight hundred ten".