666251860 has 12 divisors (see below), whose sum is σ = 1399128948. Its totient is φ = 266500736.

The previous prime is 666251809. The next prime is 666251867. The reversal of 666251860 is 68152666.

666251860 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 470195856 + 196056004 = 21684^2 + 14002^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666251867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16656277 + ... + 16656316.

It is an arithmetic number, because the mean of its divisors is an integer number (116594079).

Almost surely, 2^666251860 is an apocalyptic number.

It is an amenable number.

666251860 is an abundant number, since it is smaller than the sum of its proper divisors (732877088).

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

666251860 is a wasteful number, since it uses less digits than its factorization.

666251860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33312602 (or 33312600 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 666251860 is about 25811.8550282617. The cubic root of 666251860 is about 873.3992436449.

The spelling of 666251860 in words is "six hundred sixty-six million, two hundred fifty-one thousand, eight hundred sixty".