638455324220 has 96 divisors (see below), whose sum is σ = 1599179839488. Its totient is φ = 209346838272.

The previous prime is 638455324207. The next prime is 638455324253. The reversal of 638455324220 is 22423554836.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25512434 + ... + 25537446.

It is an arithmetic number, because the mean of its divisors is an integer number (16658123328).

Almost surely, 2^638455324220 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 638455324220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799589919744).

638455324220 is an abundant number, since it is smaller than the sum of its proper divisors (960724515268).

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

638455324220 is a wasteful number, since it uses less digits than its factorization.

638455324220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32979 (or 32977 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 44.

The spelling of 638455324220 in words is "six hundred thirty-eight billion, four hundred fifty-five million, three hundred twenty-four thousand, two hundred twenty".