638438458 has 16 divisors (see below), whose sum is σ = 1119919680. Its totient is φ = 267253056.

The previous prime is 638438341. The next prime is 638438467. The reversal of 638438458 is 854834836.

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, 529663 + ... + 530866.

It is an arithmetic number, because the mean of its divisors is an integer number (69994980).

Almost surely, 2^638438458 is an apocalyptic number.

638438458 is a deficient number, since it is larger than the sum of its proper divisors (481481222).

638438458 is a wasteful number, since it uses less digits than its factorization.

638438458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060581.

The product of its digits is 2211840, while the sum is 49.

The square root of 638438458 is about 25267.3397491703. The cubic root of 638438458 is about 861.0724218218.

The spelling of 638438458 in words is "six hundred thirty-eight million, four hundred thirty-eight thousand, four hundred fifty-eight".