638922825 has 18 divisors (see below), whose sum is σ = 1144382174. Its totient is φ = 340758720.

The previous prime is 638922821. The next prime is 638922829. The reversal of 638922825 is 528229836.

It is a happy number.

638922825 is a `hidden beast` number, since 638 + 9 + 2 + 2 + 8 + 2 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (638922821) and next prime (638922829).

It can be written as a sum of positive squares in 3 ways, for example, as 10969344 + 627953481 = 3312^2 + 25059^2 .

It is not a de Polignac number, because 638922825 - 2² = 638922821 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638922821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1419604 + ... + 1420053.

Almost surely, 2^638922825 is an apocalyptic number.

It is an amenable number.

638922825 is a deficient number, since it is larger than the sum of its proper divisors (505459349).

638922825 is a wasteful number, since it uses less digits than its factorization.

638922825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839673 (or 2839665 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 638922825 is about 25276.9227755279. The cubic root of 638922825 is about 861.2901246821.

The spelling of 638922825 in words is "six hundred thirty-eight million, nine hundred twenty-two thousand, eight hundred twenty-five".