638066880 has 252 divisors, whose sum is σ = 2413656336. Its totient is φ = 154598400.

The previous prime is 638066879. The next prime is 638066881. The reversal of 638066880 is 88660836.

638066880 is a `hidden beast` number, since 638 + 0 + 6 + 6 + 8 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (638066879) and next prime (638066881).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (638066881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 347565 + ... + 349395.

Almost surely, 2^638066880 is an apocalyptic number.

638066880 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 638066880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1206828168).

638066880 is an abundant number, since it is smaller than the sum of its proper divisors (1775589456).

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

638066880 is a wasteful number, since it uses less digits than its factorization.

638066880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876 (or 1852 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 638066880 is about 25259.9857482145. The cubic root of 638066880 is about 860.9053382880.

The spelling of 638066880 in words is "six hundred thirty-eight million, sixty-six thousand, eight hundred eighty".