666514661 has 24 divisors (see below), whose sum is σ = 725814144. Its totient is φ = 611660160.

The previous prime is 666514649. The next prime is 666514711. The reversal of 666514661 is 166415666.

It is a de Polignac number, because none of the positive numbers 2^k-666514661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666514621) 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 23 ways as a sum of consecutive naturals, for example, 2765501 + ... + 2765741.

It is an arithmetic number, because the mean of its divisors is an integer number (30242256).

Almost surely, 2^666514661 is an apocalyptic number.

It is an amenable number.

666514661 is a deficient number, since it is larger than the sum of its proper divisors (59299483).

666514661 is a wasteful number, since it uses less digits than its factorization.

666514661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 470 counting only the distinct ones).

The product of its digits is 155520, while the sum is 41.

The square root of 666514661 is about 25816.9452298292. The cubic root of 666514661 is about 873.5140650990.

The spelling of 666514661 in words is "six hundred sixty-six million, five hundred fourteen thousand, six hundred sixty-one".