668393280 has 84 divisors (see below), whose sum is σ = 2299004292. Its totient is φ = 178237440.

The previous prime is 668393279. The next prime is 668393311. The reversal of 668393280 is 82393866.

It can be written as a sum of positive squares in 2 ways, for example, as 486467136 + 181926144 = 22056^2 + 13488^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113161 + ... + 118920.

Almost surely, 2^668393280 is an apocalyptic number.

668393280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668393280 is an abundant number, since it is smaller than the sum of its proper divisors (1630611012).

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

668393280 is a wasteful number, since it uses less digits than its factorization.

668393280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232104 (or 232091 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 668393280 is about 25853.3030771698. The cubic root of 668393280 is about 874.3339824324. Note that the first 3 decimals are identical.

The spelling of 668393280 in words is "six hundred sixty-eight million, three hundred ninety-three thousand, two hundred eighty".