668686723 has 2 divisors, whose sum is σ = 668686724. Its totient is φ = 668686722.

The previous prime is 668686717. The next prime is 668686729. The reversal of 668686723 is 327686866.

It is a balanced prime because it is at equal distance from previous prime (668686717) and next prime (668686729).

It is a cyclic number.

It is not a de Polignac number, because 668686723 - 2²¹ = 666589571 is a prime.

It is not a weakly prime, because it can be changed into another prime (668686729) 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 as a sum of consecutive naturals, namely, 334343361 + 334343362.

It is an arithmetic number, because the mean of its divisors is an integer number (334343362).

Almost surely, 2^668686723 is an apocalyptic number.

668686723 is a deficient number, since it is larger than the sum of its proper divisors (1).

668686723 is an equidigital number, since it uses as much as digits as its factorization.

668686723 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 52.

The square root of 668686723 is about 25858.9776093333. The cubic root of 668686723 is about 874.4619159196.

The spelling of 668686723 in words is "six hundred sixty-eight million, six hundred eighty-six thousand, seven hundred twenty-three".