638331877 has 8 divisors (see below), whose sum is σ = 655491032. Its totient is φ = 621388800.

The previous prime is 638331853. The next prime is 638331913. The reversal of 638331877 is 778133836.

It can be written as a sum of positive squares in 4 ways, for example, as 2989441 + 635342436 = 1729^2 + 25206^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 638331877 - 2²³ = 629943269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638331377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48024 + ... + 59857.

It is an arithmetic number, because the mean of its divisors is an integer number (81936379).

Almost surely, 2^638331877 is an apocalyptic number.

It is an amenable number.

638331877 is a deficient number, since it is larger than the sum of its proper divisors (17159155).

638331877 is a wasteful number, since it uses less digits than its factorization.

638331877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108039.

The product of its digits is 508032, while the sum is 46.

The square root of 638331877 is about 25265.2305946334. The cubic root of 638331877 is about 861.0245033074.

The spelling of 638331877 in words is "six hundred thirty-eight million, three hundred thirty-one thousand, eight hundred seventy-seven".