638628480 has 384 divisors, whose sum is σ = 2581562880. Its totient is φ = 142442496.

The previous prime is 638628451. The next prime is 638628499. The reversal of 638628480 is 84826836.

It is a happy number.

638628480 is a `hidden beast` number, since 638 + 6 + 2 + 8 + 4 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×638628480² = 815692670934220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1894872 + ... + 1895208.

It is an arithmetic number, because the mean of its divisors is an integer number (6722820).

Almost surely, 2^638628480 is an apocalyptic number.

638628480 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 638628480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1290781440).

638628480 is an abundant number, since it is smaller than the sum of its proper divisors (1942934400).

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

638628480 is a wasteful number, since it uses less digits than its factorization.

638628480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 638628480 is about 25271.0996990634. The cubic root of 638628480 is about 861.1578419439.

The spelling of 638628480 in words is "six hundred thirty-eight million, six hundred twenty-eight thousand, four hundred eighty".