638726 has 8 divisors (see below), whose sum is σ = 1045224. Its totient is φ = 290320.

The previous prime is 638719. The next prime is 638767. The reversal of 638726 is 627836.

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

It is a junction number, because it is equal to n+sod(n) for n = 638692 and 638701.

It is a congruent 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, 14495 + ... + 14538.

It is an arithmetic number, because the mean of its divisors is an integer number (130653).

2⁶³⁸⁷²⁶ is an apocalyptic number.

638726 is a deficient number, since it is larger than the sum of its proper divisors (406498).

638726 is a wasteful number, since it uses less digits than its factorization.

638726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29046.

The product of its digits is 12096, while the sum is 32.

The square root of 638726 is about 799.2033533463. The cubic root of 638726 is about 86.1201673290.

The spelling of 638726 in words is "six hundred thirty-eight thousand, seven hundred twenty-six".