668833649 has 16 divisors (see below), whose sum is σ = 792821760. Its totient is φ = 557442000.

The previous prime is 668833643. The next prime is 668833651. The reversal of 668833649 is 946338866.

It is not a de Polignac number, because 668833649 - 2²⁰ = 667785073 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 668833649.

It is not an unprimeable number, because it can be changed into a prime (668833643) 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 15 ways as a sum of consecutive naturals, for example, 45137 + ... + 58094.

It is an arithmetic number, because the mean of its divisors is an integer number (49551360).

Almost surely, 2^668833649 is an apocalyptic number.

It is an amenable number.

668833649 is a deficient number, since it is larger than the sum of its proper divisors (123988111).

668833649 is a wasteful number, since it uses less digits than its factorization.

668833649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103292.

The product of its digits is 4478976, while the sum is 53.

The square root of 668833649 is about 25861.8183622111. The cubic root of 668833649 is about 874.5259577587.

The spelling of 668833649 in words is "six hundred sixty-eight million, eight hundred thirty-three thousand, six hundred forty-nine".