864638 has 8 divisors (see below), whose sum is σ = 1315440. Its totient is φ = 426160.

The previous prime is 864631. The next prime is 864641. The reversal of 864638 is 836468.

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 = 864598 and 864607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864631) by changing a digit.

864638 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2903 + ... + 3186.

It is an arithmetic number, because the mean of its divisors is an integer number (164430).

2⁸⁶⁴⁶³⁸ is an apocalyptic number.

864638 is a deficient number, since it is larger than the sum of its proper divisors (450802).

864638 is a wasteful number, since it uses less digits than its factorization.

864638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6162.

The product of its digits is 27648, while the sum is 35.

The square root of 864638 is about 929.8591291158. The cubic root of 864638 is about 95.2675009118.

It can be divided in two parts, 8 and 64638, that added together give a palindrome (64646).

The spelling of 864638 in words is "eight hundred sixty-four thousand, six hundred thirty-eight".