638868825 has 144 divisors (see below), whose sum is σ = 1416238720. Its totient is φ = 268738560.

The previous prime is 638868809. The next prime is 638868827. The reversal of 638868825 is 528868836.

It is not a de Polignac number, because 638868825 - 2⁴ = 638868809 is a prime.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (638868827) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1106937 + ... + 1107513.

Almost surely, 2^638868825 is an apocalyptic number.

It is an amenable number.

638868825 is an abundant number, since it is smaller than the sum of its proper divisors (777369895).

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

638868825 is a wasteful number, since it uses less digits than its factorization.

638868825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 648 counting only the distinct ones).

The product of its digits is 4423680, while the sum is 54.

The square root of 638868825 is about 25275.8545849591. The cubic root of 638868825 is about 861.2658593743.

The spelling of 638868825 in words is "six hundred thirty-eight million, eight hundred sixty-eight thousand, eight hundred twenty-five".