668997629 has 8 divisors (see below), whose sum is σ = 693163320. Its totient is φ = 645152256.

The previous prime is 668997601. The next prime is 668997631. The reversal of 668997629 is 926799866.

It can be written as a sum of positive squares in 4 ways, for example, as 264062500 + 404935129 = 16250^2 + 20123^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 668997629 - 2²⁰ = 667949053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668997029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75824 + ... + 84185.

It is an arithmetic number, because the mean of its divisors is an integer number (86645415).

Almost surely, 2^668997629 is an apocalyptic number.

It is an amenable number.

668997629 is a deficient number, since it is larger than the sum of its proper divisors (24165691).

668997629 is a wasteful number, since it uses less digits than its factorization.

668997629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160159.

The product of its digits is 17635968, while the sum is 62.

The square root of 668997629 is about 25864.9884786365. The cubic root of 668997629 is about 874.5974219903.

The spelling of 668997629 in words is "six hundred sixty-eight million, nine hundred ninety-seven thousand, six hundred twenty-nine".