638969454 has 24 divisors (see below), whose sum is σ = 1392933672. Its totient is φ = 211682160.

The previous prime is 638969447. The next prime is 638969477. The reversal of 638969454 is 454969836.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 638969454.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 105957 + ... + 111824.

It is an arithmetic number, because the mean of its divisors is an integer number (58038903).

Almost surely, 2^638969454 is an apocalyptic number.

638969454 is an abundant number, since it is smaller than the sum of its proper divisors (753964218).

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

638969454 is a wasteful number, since it uses less digits than its factorization.

638969454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217952 (or 217949 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The square root of 638969454 is about 25277.8451217662. The cubic root of 638969454 is about 861.3110766754.

The spelling of 638969454 in words is "six hundred thirty-eight million, nine hundred sixty-nine thousand, four hundred fifty-four".