666541860 has 24 divisors (see below), whose sum is σ = 1866317376. Its totient is φ = 177744480.

The previous prime is 666541859. The next prime is 666541861. The reversal of 666541860 is 68145666.

It is an interprime number because it is at equal distance from previous prime (666541859) and next prime (666541861).

It is a super-2 number, since 2×666541860² = 888556102264519200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666541861) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5554456 + ... + 5554575.

It is an arithmetic number, because the mean of its divisors is an integer number (77763224).

Almost surely, 2^666541860 is an apocalyptic number.

666541860 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666541860 is an abundant number, since it is smaller than the sum of its proper divisors (1199775516).

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

666541860 is a wasteful number, since it uses less digits than its factorization.

666541860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11109043 (or 11109041 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The square root of 666541860 is about 25817.4719908825. The cubic root of 666541860 is about 873.5259470011.

The spelling of 666541860 in words is "six hundred sixty-six million, five hundred forty-one thousand, eight hundred sixty".