638433072 has 30 divisors (see below), whose sum is σ = 1786726292. Its totient is φ = 212810976.

The previous prime is 638433043. The next prime is 638433077. The reversal of 638433072 is 270334836.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (638433077) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2216638 + ... + 2216925.

Almost surely, 2^638433072 is an apocalyptic number.

It is an amenable number.

638433072 is an abundant number, since it is smaller than the sum of its proper divisors (1148293220).

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

638433072 is a wasteful number, since it uses less digits than its factorization.

638433072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4433577 (or 4433568 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 638433072 is about 25267.2331686712. The cubic root of 638433072 is about 861.0700004194.

The spelling of 638433072 in words is "six hundred thirty-eight million, four hundred thirty-three thousand, seventy-two".