668836829 has 2 divisors, whose sum is σ = 668836830. Its totient is φ = 668836828.

The previous prime is 668836807. The next prime is 668836859. The reversal of 668836829 is 928638866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 655257604 + 13579225 = 25598^2 + 3685^2 .

It is a cyclic number.

It is not a de Polignac number, because 668836829 - 2¹² = 668832733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668836859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334418414 + 334418415.

It is an arithmetic number, because the mean of its divisors is an integer number (334418415).

Almost surely, 2^668836829 is an apocalyptic number.

It is an amenable number.

668836829 is a deficient number, since it is larger than the sum of its proper divisors (1).

668836829 is an equidigital number, since it uses as much as digits as its factorization.

668836829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5971968, while the sum is 56.

The square root of 668836829 is about 25861.8798427338. The cubic root of 668836829 is about 874.5273437476.

The spelling of 668836829 in words is "six hundred sixty-eight million, eight hundred thirty-six thousand, eight hundred twenty-nine".