638774442 has 12 divisors (see below), whose sum is σ = 1384011330. Its totient is φ = 212924808.

The previous prime is 638774431. The next prime is 638774447. The reversal of 638774442 is 244477836.

638774442 is a `hidden beast` number, since 63 + 87 + 74 + 442 = 666.

It can be written as a sum of positive squares in only one way, i.e., 538193601 + 100580841 = 23199^2 + 10029^2 .

It is a super-2 number, since 2×638774442² = 816065575504822728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638774447) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17743717 + ... + 17743752.

Almost surely, 2^638774442 is an apocalyptic number.

638774442 is an abundant number, since it is smaller than the sum of its proper divisors (745236888).

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

638774442 is a wasteful number, since it uses less digits than its factorization.

638774442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35487477 (or 35487474 counting only the distinct ones).

The product of its digits is 903168, while the sum is 45.

The square root of 638774442 is about 25273.9874574631. The cubic root of 638774442 is about 861.2234443767.

The spelling of 638774442 in words is "six hundred thirty-eight million, seven hundred seventy-four thousand, four hundred forty-two".