638131072 has 16 divisors (see below), whose sum is σ = 1271277000. Its totient is φ = 319065472.

The previous prime is 638131061. The next prime is 638131073. The reversal of 638131072 is 270131836.

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×638131072² = 814422530103738368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638131073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2492572 + ... + 2492827.

Almost surely, 2^638131072 is an apocalyptic number.

It is an amenable number.

638131072 is a deficient number, since it is larger than the sum of its proper divisors (633145928).

638131072 is an equidigital number, since it uses as much as digits as its factorization.

638131072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4985413 (or 4985401 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 638131072 is about 25261.2563424704. The cubic root of 638131072 is about 860.9342074573.

The spelling of 638131072 in words is "six hundred thirty-eight million, one hundred thirty-one thousand, seventy-two".