638975 has 12 divisors (see below), whose sum is σ = 807240. Its totient is φ = 501600.

The previous prime is 638971. The next prime is 638977. The reversal of 638975 is 579836.

It is not a de Polignac number, because 638975 - 2² = 638971 is a prime.

It is a plaindrome in base 8 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638971) 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 11 ways as a sum of consecutive naturals, for example, 1316 + ... + 1734.

It is an arithmetic number, because the mean of its divisors is an integer number (67270).

2⁶³⁸⁹⁷⁵ is an apocalyptic number.

638975 is a deficient number, since it is larger than the sum of its proper divisors (168265).

638975 is a wasteful number, since it uses less digits than its factorization.

638975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490 (or 485 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 638975 is about 799.3591182941. The cubic root of 638975 is about 86.1313568614.

The spelling of 638975 in words is "six hundred thirty-eight thousand, nine hundred seventy-five".