638955 has 16 divisors (see below), whose sum is σ = 1136160. Its totient is φ = 340704.

The previous prime is 638933. The next prime is 638959. The reversal of 638955 is 559836.

It is not a de Polignac number, because 638955 - 2⁵ = 638923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2232 + ... + 2501.

It is an arithmetic number, because the mean of its divisors is an integer number (71010).

2⁶³⁸⁹⁵⁵ is an apocalyptic number.

638955 is a deficient number, since it is larger than the sum of its proper divisors (497205).

638955 is a wasteful number, since it uses less digits than its factorization.

638955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4747 (or 4741 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 638955 is about 799.3466081745. The cubic root of 638955 is about 86.1304582111.

The spelling of 638955 in words is "six hundred thirty-eight thousand, nine hundred fifty-five".