638544480 has 288 divisors, whose sum is σ = 2478996576. Its totient is φ = 137281536.

The previous prime is 638544451. The next prime is 638544493. The reversal of 638544480 is 84445836.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 399042 + ... + 400638.

It is an arithmetic number, because the mean of its divisors is an integer number (8607627).

Almost surely, 2^638544480 is an apocalyptic number.

638544480 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638544480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1239498288).

638544480 is an abundant number, since it is smaller than the sum of its proper divisors (1840452096).

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

638544480 is a wasteful number, since it uses less digits than its factorization.

638544480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1646 (or 1631 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 42.

The square root of 638544480 is about 25269.4376668734. The cubic root of 638544480 is about 861.1200837204.

The spelling of 638544480 in words is "six hundred thirty-eight million, five hundred forty-four thousand, four hundred eighty".