638764474 has 8 divisors (see below), whose sum is σ = 958338900. Its totient is φ = 319318176.

The previous prime is 638764471. The next prime is 638764499. The reversal of 638764474 is 474467836.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 627252025 + 11512449 = 25045^2 + 3393^2 .

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

It is not an unprimeable number, because it can be changed into a prime (638764471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18409 + ... + 40204.

Almost surely, 2^638764474 is an apocalyptic number.

638764474 is a deficient number, since it is larger than the sum of its proper divisors (319574426).

638764474 is a wasteful number, since it uses less digits than its factorization.

638764474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64064.

The product of its digits is 2709504, while the sum is 49.

The square root of 638764474 is about 25273.7902578937. The cubic root of 638764474 is about 861.2189645899.

The spelling of 638764474 in words is "six hundred thirty-eight million, seven hundred sixty-four thousand, four hundred seventy-four".