666918449 has 8 divisors (see below), whose sum is σ = 743315040. Its totient is φ = 594651456.

The previous prime is 666918431. The next prime is 666918457. The reversal of 666918449 is 944819666.

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 666918449 - 2⁸ = 666918193 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666918449.

It is not an unprimeable number, because it can be changed into a prime (666918479) 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, 1032059 + ... + 1032704.

It is an arithmetic number, because the mean of its divisors is an integer number (92914380).

Almost surely, 2^666918449 is an apocalyptic number.

It is an amenable number.

666918449 is a deficient number, since it is larger than the sum of its proper divisors (76396591).

666918449 is a wasteful number, since it uses less digits than its factorization.

666918449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2064799.

The product of its digits is 2239488, while the sum is 53.

The square root of 666918449 is about 25824.7642583626. The cubic root of 666918449 is about 873.6904269581.

The spelling of 666918449 in words is "six hundred sixty-six million, nine hundred eighteen thousand, four hundred forty-nine".