638822880 has 144 divisors (see below), whose sum is σ = 2189363904. Its totient is φ = 169620480.

The previous prime is 638822851. The next prime is 638822881. The reversal of 638822880 is 88228836.

638822880 is a `hidden beast` number, since 638 + 8 + 2 + 2 + 8 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×638822880² = 816189344022988800, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638822881) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 389422 + ... + 391058.

It is an arithmetic number, because the mean of its divisors is an integer number (15203916).

Almost surely, 2^638822880 is an apocalyptic number.

638822880 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 638822880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1094681952).

638822880 is an abundant number, since it is smaller than the sum of its proper divisors (1550541024).

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

638822880 is a wasteful number, since it uses less digits than its factorization.

638822880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1929 (or 1918 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 638822880 is about 25274.9456972710. The cubic root of 638822880 is about 861.2452125649.

The spelling of 638822880 in words is "six hundred thirty-eight million, eight hundred twenty-two thousand, eight hundred eighty".