638902080 has 210 divisors, whose sum is σ = 2287255014. Its totient is φ = 169288704.

The previous prime is 638902031. The next prime is 638902093. The reversal of 638902080 is 80209836.

It can be written as a sum of positive squares in 3 ways, for example, as 7485696 + 631416384 = 2736^2 + 25128^2 .

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

It is a congruent number.

It is an unprimeable number.

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 29 ways as a sum of consecutive naturals, for example, 4069362 + ... + 4069518.

Almost surely, 2^638902080 is an apocalyptic number.

638902080 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 638902080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1143627507).

638902080 is an abundant number, since it is smaller than the sum of its proper divisors (1648352934).

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

638902080 is an equidigital number, since it uses as much as digits as its factorization.

638902080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 638902080 is about 25276.5124176576. The cubic root of 638902080 is about 861.2808029214.

The spelling of 638902080 in words is "six hundred thirty-eight million, nine hundred two thousand, eighty".