638402612 has 6 divisors (see below), whose sum is σ = 1117204578. Its totient is φ = 319201304.

The previous prime is 638402587. The next prime is 638402617. The reversal of 638402612 is 216204836.

It can be written as a sum of positive squares in only one way, i.e., 480749476 + 157653136 = 21926^2 + 12556^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638402617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79800323 + ... + 79800330.

It is an arithmetic number, because the mean of its divisors is an integer number (186200763).

Almost surely, 2^638402612 is an apocalyptic number.

It is an amenable number.

638402612 is a deficient number, since it is larger than the sum of its proper divisors (478801966).

638402612 is a wasteful number, since it uses less digits than its factorization.

638402612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159600657 (or 159600655 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 638402612 is about 25266.6304045474. The cubic root of 638402612 is about 861.0563061574.

The spelling of 638402612 in words is "six hundred thirty-eight million, four hundred two thousand, six hundred twelve".