666860256 has 192 divisors, whose sum is σ = 2010254400. Its totient is φ = 214990848.

The previous prime is 666860231. The next prime is 666860267. The reversal of 666860256 is 652068666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6117930 + ... + 6118038.

It is an arithmetic number, because the mean of its divisors is an integer number (10470075).

Almost surely, 2^666860256 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 666860256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1005127200).

666860256 is an abundant number, since it is smaller than the sum of its proper divisors (1343394144).

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

666860256 is a wasteful number, since it uses less digits than its factorization.

666860256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 666860256 is about 25823.6375439248. The cubic root of 666860256 is about 873.6650144828.

The spelling of 666860256 in words is "six hundred sixty-six million, eight hundred sixty thousand, two hundred fifty-six".