638461572 has 96 divisors (see below), whose sum is σ = 1748947200. Its totient is φ = 181198080.

The previous prime is 638461567. The next prime is 638461589. The reversal of 638461572 is 275164836.

It is a super-2 number, since 2×638461572² = 815266357841422368, which contains 22 as substring.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

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 31 ways as a sum of consecutive naturals, for example, 744568 + ... + 745424.

It is an arithmetic number, because the mean of its divisors is an integer number (18218200).

Almost surely, 2^638461572 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638461572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (874473600).

638461572 is an abundant number, since it is smaller than the sum of its proper divisors (1110485628).

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

638461572 is a wasteful number, since it uses less digits than its factorization.

638461572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1066 (or 1050 counting only the distinct ones).

The product of its digits is 241920, while the sum is 42.

The square root of 638461572 is about 25267.7971339015. The cubic root of 638461572 is about 861.0828131067.

The spelling of 638461572 in words is "six hundred thirty-eight million, four hundred sixty-one thousand, five hundred seventy-two".