638746 has 8 divisors (see below), whose sum is σ = 961524. Its totient is φ = 318240.

The previous prime is 638719. The next prime is 638767. The reversal of 638746 is 647836.

It can be written as a sum of positive squares in 2 ways, for example, as 505521 + 133225 = 711^2 + 365^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 736 + ... + 1348.

2⁶³⁸⁷⁴⁶ is an apocalyptic number.

638746 is a deficient number, since it is larger than the sum of its proper divisors (322778).

638746 is a wasteful number, since it uses less digits than its factorization.

638746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136.

The product of its digits is 24192, while the sum is 34.

The square root of 638746 is about 799.2158657084. The cubic root of 638746 is about 86.1210661940.

The spelling of 638746 in words is "six hundred thirty-eight thousand, seven hundred forty-six".