638155 has 8 divisors (see below), whose sum is σ = 875232. Its totient is φ = 437568.

The previous prime is 638147. The next prime is 638159. The reversal of 638155 is 551836.

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

It is a cyclic number.

It is not a de Polignac number, because 638155 - 2³ = 638147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638159) 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, 9082 + ... + 9151.

It is an arithmetic number, because the mean of its divisors is an integer number (109404).

2⁶³⁸¹⁵⁵ is an apocalyptic number.

638155 is a deficient number, since it is larger than the sum of its proper divisors (237077).

638155 is a wasteful number, since it uses less digits than its factorization.

638155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18245.

The product of its digits is 3600, while the sum is 28.

The square root of 638155 is about 798.8460427392. The cubic root of 638155 is about 86.0944968139.

The spelling of 638155 in words is "six hundred thirty-eight thousand, one hundred fifty-five".