638406272 has 32 divisors (see below), whose sum is σ = 1453516320. Its totient is φ = 273602304.

The previous prime is 638406259. The next prime is 638406299. The reversal of 638406272 is 272604836.

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 355358 + ... + 357149.

It is an arithmetic number, because the mean of its divisors is an integer number (45422385).

Almost surely, 2^638406272 is an apocalyptic number.

It is an amenable number.

638406272 is an abundant number, since it is smaller than the sum of its proper divisors (815110048).

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

638406272 is an equidigital number, since it uses as much as digits as its factorization.

638406272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712528 (or 712516 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 38.

The square root of 638406272 is about 25266.7028319882. The cubic root of 638406272 is about 861.0579516499.

The spelling of 638406272 in words is "six hundred thirty-eight million, four hundred six thousand, two hundred seventy-two".