668366497 has 4 divisors (see below), whose sum is σ = 668529796. Its totient is φ = 668203200.

The previous prime is 668366471. The next prime is 668366513. The reversal of 668366497 is 794663866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21986721 + 646379776 = 4689^2 + 25424^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668366497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668366437) 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 3 ways as a sum of consecutive naturals, for example, 75348 + ... + 83749.

It is an arithmetic number, because the mean of its divisors is an integer number (167132449).

Almost surely, 2^668366497 is an apocalyptic number.

It is an amenable number.

668366497 is a deficient number, since it is larger than the sum of its proper divisors (163299).

668366497 is a wasteful number, since it uses less digits than its factorization.

668366497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163298.

The product of its digits is 7838208, while the sum is 55.

The square root of 668366497 is about 25852.7850917459. The cubic root of 668366497 is about 874.3223038790.

The spelling of 668366497 in words is "six hundred sixty-eight million, three hundred sixty-six thousand, four hundred ninety-seven".