666665477 has 8 divisors (see below), whose sum is σ = 678381600. Its totient is φ = 655001424.

The previous prime is 666665449. The next prime is 666665551. The reversal of 666665477 is 774566666.

It is a happy number.

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 666665477 - 2¹² = 666661381 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 (666665677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13274 + ... + 38852.

It is an arithmetic number, because the mean of its divisors is an integer number (84797700).

Almost surely, 2^666665477 is an apocalyptic number.

666665477 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

666665477 is a deficient number, since it is larger than the sum of its proper divisors (11716123).

666665477 is a wasteful number, since it uses less digits than its factorization.

666665477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26035.

The product of its digits is 7620480, while the sum is 53.

The square root of 666665477 is about 25819.8659369099. The cubic root of 666665477 is about 873.5799451012.

The spelling of 666665477 in words is "six hundred sixty-six million, six hundred sixty-five thousand, four hundred seventy-seven".