638606425 has 6 divisors (see below), whose sum is σ = 791871998. Its totient is φ = 510885120.

The previous prime is 638606393. The next prime is 638606443. The reversal of 638606425 is 524606836.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 120406729 + 518199696 = 10973^2 + 22764^2 .

It is not a de Polignac number, because 638606425 - 2⁵ = 638606393 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12772104 + ... + 12772153.

Almost surely, 2^638606425 is an apocalyptic number.

It is an amenable number.

638606425 is a deficient number, since it is larger than the sum of its proper divisors (153265573).

638606425 is a wasteful number, since it uses less digits than its factorization.

638606425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25544267 (or 25544262 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 638606425 is about 25270.6633272655. The cubic root of 638606425 is about 861.1479284833.

The spelling of 638606425 in words is "six hundred thirty-eight million, six hundred six thousand, four hundred twenty-five".