638853120 has 168 divisors, whose sum is σ = 2215833516. Its totient is φ = 170262528.

The previous prime is 638853119. The next prime is 638853143. The reversal of 638853120 is 21358836.

638853120 is a `hidden beast` number, since 638 + 8 + 5 + 3 + 12 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 632623104 + 6230016 = 25152^2 + 2496^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 367774 + ... + 369506.

Almost surely, 2^638853120 is an apocalyptic number.

638853120 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 638853120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1107916758).

638853120 is an abundant number, since it is smaller than the sum of its proper divisors (1576980396).

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

638853120 is a wasteful number, since it uses less digits than its factorization.

638853120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1770 (or 1743 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 638853120 is about 25275.5439110615. The cubic root of 638853120 is about 861.2588019573.

The spelling of 638853120 in words is "six hundred thirty-eight million, eight hundred fifty-three thousand, one hundred twenty".