638772 has 12 divisors (see below), whose sum is σ = 1490496. Its totient is φ = 212920.

The previous prime is 638767. The next prime is 638801. The reversal of 638772 is 277836.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638772.

It is an unprimeable number.

638772 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, 26604 + ... + 26627.

It is an arithmetic number, because the mean of its divisors is an integer number (124208).

2⁶³⁸⁷⁷² is an apocalyptic number.

It is an amenable number.

638772 is an abundant number, since it is smaller than the sum of its proper divisors (851724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638772 is a wasteful number, since it uses less digits than its factorization.

638772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53238 (or 53236 counting only the distinct ones).

The product of its digits is 14112, while the sum is 33.

The square root of 638772 is about 799.2321314862. The cubic root of 638772 is about 86.1222346905.

The spelling of 638772 in words is "six hundred thirty-eight thousand, seven hundred seventy-two".