667128384 has 252 divisors, whose sum is σ = 2150572788. Its totient is φ = 196485120.

The previous prime is 667128379. The next prime is 667128443. The reversal of 667128384 is 483821766.

It can be written as a sum of positive squares in 6 ways, for example, as 241118784 + 426009600 = 15528^2 + 20640^2 .

Its product of digits (387072) is a multiple of the sum of its prime divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 12587302 + ... + 12587354.

It is an arithmetic number, because the mean of its divisors is an integer number (8534019).

Almost surely, 2^667128384 is an apocalyptic number.

667128384 is a gapful number since it is divisible by the number (64) 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 667128384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1075286394).

667128384 is an abundant number, since it is smaller than the sum of its proper divisors (1483444404).

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

667128384 is a wasteful number, since it uses less digits than its factorization.

667128384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 112 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 667128384 is about 25828.8285448644. The cubic root of 667128384 is about 873.7820918174.

The spelling of 667128384 in words is "six hundred sixty-seven million, one hundred twenty-eight thousand, three hundred eighty-four".