638452636 has 12 divisors (see below), whose sum is σ = 1121745240. Its totient is φ = 317954000.

The previous prime is 638452631. The next prime is 638452637. The reversal of 638452636 is 636254836.

It is a junction number, because it is equal to n+sod(n) for n = 638452592 and 638452601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638452631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 316951 + ... + 318958.

It is an arithmetic number, because the mean of its divisors is an integer number (93478770).

Almost surely, 2^638452636 is an apocalyptic number.

It is an amenable number.

638452636 is a deficient number, since it is larger than the sum of its proper divisors (483292604).

638452636 is a wasteful number, since it uses less digits than its factorization.

638452636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636164 (or 636162 counting only the distinct ones).

The product of its digits is 622080, while the sum is 43.

The square root of 638452636 is about 25267.6203074211. The cubic root of 638452636 is about 861.0787958083.

The spelling of 638452636 in words is "six hundred thirty-eight million, four hundred fifty-two thousand, six hundred thirty-six".