638886 has 16 divisors (see below), whose sum is σ = 1286064. Its totient is φ = 211584.

The previous prime is 638861. The next prime is 638893. The reversal of 638886 is 688836.

It is a congruent number.

It is an unprimeable number.

638886 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1170 + ... + 1626.

It is an arithmetic number, because the mean of its divisors is an integer number (80379).

2⁶³⁸⁸⁸⁶ is an apocalyptic number.

638886 is an abundant number, since it is smaller than the sum of its proper divisors (647178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638886 is a wasteful number, since it uses less digits than its factorization.

638886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695.

The product of its digits is 55296, while the sum is 39.

The square root of 638886 is about 799.3034467585. The cubic root of 638886 is about 86.1273577239.

The spelling of 638886 in words is "six hundred thirty-eight thousand, eight hundred eighty-six".