638285090 has 16 divisors (see below), whose sum is σ = 1167748920. Its totient is φ = 251128320.

The previous prime is 638285033. The next prime is 638285117. The reversal of 638285090 is 90582836.

It can be written as a sum of positive squares in 4 ways, for example, as 413674921 + 224610169 = 20339^2 + 14987^2 .

It is a super-2 number, since 2×638285090² = 814815712232616200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 522575 + ... + 523794.

Almost surely, 2^638285090 is an apocalyptic number.

638285090 is a deficient number, since it is larger than the sum of its proper divisors (529463830).

638285090 is a wasteful number, since it uses less digits than its factorization.

638285090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046437.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 638285090 is about 25264.3046609243. The cubic root of 638285090 is about 861.0034663207.

The spelling of 638285090 in words is "six hundred thirty-eight million, two hundred eighty-five thousand, ninety".