668535629 has 2 divisors, whose sum is σ = 668535630. Its totient is φ = 668535628.

The previous prime is 668535617. The next prime is 668535649. The reversal of 668535629 is 926535866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 466128100 + 202407529 = 21590^2 + 14227^2 .

It is a cyclic number.

It is not a de Polignac number, because 668535629 - 2¹² = 668531533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668535649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334267814 + 334267815.

It is an arithmetic number, because the mean of its divisors is an integer number (334267815).

Almost surely, 2^668535629 is an apocalyptic number.

It is an amenable number.

668535629 is a deficient number, since it is larger than the sum of its proper divisors (1).

668535629 is an equidigital number, since it uses as much as digits as its factorization.

668535629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2332800, while the sum is 50.

The square root of 668535629 is about 25856.0559444011. The cubic root of 668535629 is about 874.3960475555.

The spelling of 668535629 in words is "six hundred sixty-eight million, five hundred thirty-five thousand, six hundred twenty-nine".