638397 has 12 divisors (see below), whose sum is σ = 933660. Its totient is φ = 420288.

The previous prime is 638371. The next prime is 638423. The reversal of 638397 is 793836.

It is an interprime number because it is at equal distance from previous prime (638371) and next prime (638423).

It can be written as a sum of positive squares in 2 ways, for example, as 210681 + 427716 = 459^2 + 654^2 .

It is not a de Polignac number, because 638397 - 2⁷ = 638269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638317) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 403 + ... + 1199.

It is an arithmetic number, because the mean of its divisors is an integer number (77805).

2⁶³⁸³⁹⁷ is an apocalyptic number.

It is an amenable number.

638397 is a deficient number, since it is larger than the sum of its proper divisors (295263).

638397 is a wasteful number, since it uses less digits than its factorization.

638397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892 (or 889 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 638397 is about 798.9974968672. The cubic root of 638397 is about 86.1053783057.

It can be divided in two parts, 638 and 397, that added together give a triangular number (1035 = T₄₅).

The spelling of 638397 in words is "six hundred thirty-eight thousand, three hundred ninety-seven".