666546669 has 6 divisors (see below), whose sum is σ = 962789646. Its totient is φ = 444364440.

The previous prime is 666546653. The next prime is 666546691. The reversal of 666546669 is 966645666.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 591948900 + 74597769 = 24330^2 + 8637^2 .

It is not a de Polignac number, because 666546669 - 2⁴ = 666546653 is a prime.

It is a super-2 number, since 2×666546669² = 888568923909991122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666546649) 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 5 ways as a sum of consecutive naturals, for example, 37030362 + ... + 37030379.

It is an arithmetic number, because the mean of its divisors is an integer number (160464941).

Almost surely, 2^666546669 is an apocalyptic number.

It is an amenable number.

666546669 is a deficient number, since it is larger than the sum of its proper divisors (296242977).

666546669 is a wasteful number, since it uses less digits than its factorization.

666546669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74060747 (or 74060744 counting only the distinct ones).

The product of its digits is 8398080, while the sum is 54.

The square root of 666546669 is about 25817.5651253173. The cubic root of 666546669 is about 873.5280477825.

The spelling of 666546669 in words is "six hundred sixty-six million, five hundred forty-six thousand, six hundred sixty-nine".