666876681 has 48 divisors (see below), whose sum is σ = 1019566080. Its totient is φ = 419489280.

The previous prime is 666876673. The next prime is 666876709. The reversal of 666876681 is 186678666.

It is not a de Polignac number, because 666876681 - 2³ = 666876673 is a prime.

It is a super-2 number, since 2×666876681² = 889449015323151522, which contains 22 as substring.

Its product of digits (3483648) is a multiple of the sum of its prime factors (486).

It is not an unprimeable number, because it can be changed into a prime (666876631) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 2790160 + ... + 2790398.

It is an arithmetic number, because the mean of its divisors is an integer number (21240960).

Almost surely, 2^666876681 is an apocalyptic number.

It is an amenable number.

666876681 is a deficient number, since it is larger than the sum of its proper divisors (352689399).

666876681 is a wasteful number, since it uses less digits than its factorization.

666876681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486 (or 483 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 54.

The square root of 666876681 is about 25823.9555645528. The cubic root of 666876681 is about 873.6721873149.

The spelling of 666876681 in words is "six hundred sixty-six million, eight hundred seventy-six thousand, six hundred eighty-one".