668929 has 2 divisors, whose sum is σ = 668930. Its totient is φ = 668928.

The previous prime is 668903. The next prime is 668939. The reversal of 668929 is 929866.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 490000 + 178929 = 700^2 + 423^2 .

It is a cyclic number.

It is not a de Polignac number, because 668929 - 2⁹ = 668417 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 668891 and 668900.

It is not a weakly prime, because it can be changed into another prime (668939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334464 + 334465.

It is an arithmetic number, because the mean of its divisors is an integer number (334465).

2⁶⁶⁸⁹²⁹ is an apocalyptic number.

It is an amenable number.

668929 is a deficient number, since it is larger than the sum of its proper divisors (1).

668929 is an equidigital number, since it uses as much as digits as its factorization.

668929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 40.

The square root of 668929 is about 817.8807981607. The cubic root of 668929 is about 87.4567514162.

The spelling of 668929 in words is "six hundred sixty-eight thousand, nine hundred twenty-nine".