638077506 has 64 divisors (see below), whose sum is σ = 1464898176. Its totient is φ = 183513600.

The previous prime is 638077483. The next prime is 638077519. The reversal of 638077506 is 605770836.

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, 96936 + ... + 103308.

It is an arithmetic number, because the mean of its divisors is an integer number (22889034).

Almost surely, 2^638077506 is an apocalyptic number.

638077506 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 638077506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (732449088).

638077506 is an abundant number, since it is smaller than the sum of its proper divisors (826820670).

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

638077506 is a wasteful number, since it uses less digits than its factorization.

638077506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6467.

The product of its (nonzero) digits is 211680, while the sum is 42.

The square root of 638077506 is about 25260.1960799991. The cubic root of 638077506 is about 860.9101172694.

The spelling of 638077506 in words is "six hundred thirty-eight million, seventy-seven thousand, five hundred six".