666676747781 has 8 divisors (see below), whose sum is σ = 727311247104. Its totient is φ = 606046835520.

The previous prime is 666676747757. The next prime is 666676747783. The reversal of 666676747781 is 187747676666.

666676747781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666676747781 - 2³⁰ = 665603005957 is a prime.

It is a super-2 number, since 2×666676747781² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666676747783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 839285 + ... + 1427498.

It is an arithmetic number, because the mean of its divisors is an integer number (90913905888).

Almost surely, 2^666676747781 is an apocalyptic number.

It is an amenable number.

666676747781 is a deficient number, since it is larger than the sum of its proper divisors (60634499323).

666676747781 is a wasteful number, since it uses less digits than its factorization.

666676747781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2293531.

The product of its digits is 597445632, while the sum is 71.

The spelling of 666676747781 in words is "six hundred sixty-six billion, six hundred seventy-six million, seven hundred forty-seven thousand, seven hundred eighty-one".