638458490 has 16 divisors (see below), whose sum is σ = 1188854280. Its totient is φ = 246576960.

The previous prime is 638458459. The next prime is 638458507. The reversal of 638458490 is 94854836.

It can be written as a sum of positive squares in 4 ways, for example, as 601868089 + 36590401 = 24533^2 + 6049^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1100501 + ... + 1101080.

Almost surely, 2^638458490 is an apocalyptic number.

638458490 is a deficient number, since it is larger than the sum of its proper divisors (550395790).

638458490 is a wasteful number, since it uses less digits than its factorization.

638458490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2201617.

The product of its (nonzero) digits is 829440, while the sum is 47.

The square root of 638458490 is about 25267.7361471106. The cubic root of 638458490 is about 861.0814275566.

The spelling of 638458490 in words is "six hundred thirty-eight million, four hundred fifty-eight thousand, four hundred ninety".