666879577 has 32 divisors (see below), whose sum is σ = 835627520. Its totient is φ = 521277120.

The previous prime is 666879541. The next prime is 666879583. The reversal of 666879577 is 775978666.

It is not a de Polignac number, because 666879577 - 2²³ = 658490969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666873577) 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 31 ways as a sum of consecutive naturals, for example, 1583827 + ... + 1584247.

It is an arithmetic number, because the mean of its divisors is an integer number (26113360).

Almost surely, 2^666879577 is an apocalyptic number.

It is an amenable number.

666879577 is a deficient number, since it is larger than the sum of its proper divisors (168747943).

666879577 is a wasteful number, since it uses less digits than its factorization.

666879577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570 (or 544 counting only the distinct ones).

The product of its digits is 26671680, while the sum is 61.

The square root of 666879577 is about 25824.0116364596. The cubic root of 666879577 is about 873.6734519920.

The spelling of 666879577 in words is "six hundred sixty-six million, eight hundred seventy-nine thousand, five hundred seventy-seven".