638198454 has 16 divisors (see below), whose sum is σ = 1291776192. Its totient is φ = 210169608.

The previous prime is 638198453. The next prime is 638198507. The reversal of 638198454 is 454891836.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638198453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 640264 + ... + 641259.

It is an arithmetic number, because the mean of its divisors is an integer number (80736012).

Almost surely, 2^638198454 is an apocalyptic number.

638198454 is an abundant number, since it is smaller than the sum of its proper divisors (653577738).

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

638198454 is a wasteful number, since it uses less digits than its factorization.

638198454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1281611.

The product of its digits is 829440, while the sum is 48.

The square root of 638198454 is about 25262.5900097357. The cubic root of 638198454 is about 860.9645091877.

The spelling of 638198454 in words is "six hundred thirty-eight million, one hundred ninety-eight thousand, four hundred fifty-four".