638131 has 8 divisors (see below), whose sum is σ = 693504. Its totient is φ = 583680.

The previous prime is 638123. The next prime is 638147. The reversal of 638131 is 131836.

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 638131 - 2³ = 638123 is a prime.

It is a super-2 number, since 2×638131² = 814422346322, which contains 22 as substring.

It is a Duffinian number.

638131 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (638161) 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, 2355 + ... + 2611.

It is an arithmetic number, because the mean of its divisors is an integer number (86688).

2⁶³⁸¹³¹ is an apocalyptic number.

638131 is a deficient number, since it is larger than the sum of its proper divisors (55373).

638131 is a wasteful number, since it uses less digits than its factorization.

638131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461.

The product of its digits is 432, while the sum is 22.

The square root of 638131 is about 798.8310209300. The cubic root of 638131 is about 86.0934175078.

Adding to 638131 its reverse (131836), we get a palindrome (769967).

The spelling of 638131 in words is "six hundred thirty-eight thousand, one hundred thirty-one".