638709120 has 576 divisors, whose sum is σ = 2684672640. Its totient is φ = 139345920.

The previous prime is 638709119. The next prime is 638709121. The reversal of 638709120 is 21907836.

638709120 is a `hidden beast` number, since 638 + 7 + 0 + 9 + 12 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (638709119) and next prime (638709121).

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638709121) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8749404 + ... + 8749476.

It is an arithmetic number, because the mean of its divisors is an integer number (4660890).

Almost surely, 2^638709120 is an apocalyptic number.

638709120 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 638709120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1342336320).

638709120 is an abundant number, since it is smaller than the sum of its proper divisors (2045963520).

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

638709120 is a wasteful number, since it uses less digits than its factorization.

638709120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 638709120 is about 25272.6951471346. The cubic root of 638709120 is about 861.1940867236.

The spelling of 638709120 in words is "six hundred thirty-eight million, seven hundred nine thousand, one hundred twenty".