638465 has 8 divisors (see below), whose sum is σ = 772200. Its totient is φ = 506752.

The previous prime is 638459. The next prime is 638467. The reversal of 638465 is 564836.

It can be written as a sum of positive squares in 4 ways, for example, as 78961 + 559504 = 281^2 + 748^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638465 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317 + ... + 1173.

It is an arithmetic number, because the mean of its divisors is an integer number (96525).

2⁶³⁸⁴⁶⁵ is an apocalyptic number.

It is an amenable number.

638465 is a deficient number, since it is larger than the sum of its proper divisors (133735).

638465 is a wasteful number, since it uses less digits than its factorization.

638465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011.

The product of its digits is 17280, while the sum is 32.

The square root of 638465 is about 799.0400490589. The cubic root of 638465 is about 86.1084354200.

The spelling of 638465 in words is "six hundred thirty-eight thousand, four hundred sixty-five".