638078080 has 64 divisors (see below), whose sum is σ = 1562674680. Its totient is φ = 248995840.

The previous prime is 638078071. The next prime is 638078101. The reversal of 638078080 is 80870836.

It can be written as a sum of positive squares in 4 ways, for example, as 402885184 + 235192896 = 20072^2 + 15336^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14082 + ... + 38398.

Almost surely, 2^638078080 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 638078080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781337340).

638078080 is an abundant number, since it is smaller than the sum of its proper divisors (924596600).

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

638078080 is a wasteful number, since it uses less digits than its factorization.

638078080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24377 (or 24365 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 638078080 is about 25260.2074417452. The cubic root of 638078080 is about 860.9103754211.

The spelling of 638078080 in words is "six hundred thirty-eight million, seventy-eight thousand, eighty".