638786 has 8 divisors (see below), whose sum is σ = 989184. Its totient is φ = 309060.

The previous prime is 638767. The next prime is 638801. The reversal of 638786 is 687836.

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

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5090 + ... + 5213.

It is an arithmetic number, because the mean of its divisors is an integer number (123648).

2⁶³⁸⁷⁸⁶ is an apocalyptic number.

638786 is a deficient number, since it is larger than the sum of its proper divisors (350398).

638786 is a wasteful number, since it uses less digits than its factorization.

638786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10336.

The product of its digits is 48384, while the sum is 38.

The square root of 638786 is about 799.2408898449. The cubic root of 638786 is about 86.1228638678.

The spelling of 638786 in words is "six hundred thirty-eight thousand, seven hundred eighty-six".