668643337 has 4 divisors (see below), whose sum is σ = 707975316. Its totient is φ = 629311360.

The previous prime is 668643323. The next prime is 668643341. The reversal of 668643337 is 733346866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 181602576 + 487040761 = 13476^2 + 22069^2 .

It is a cyclic number.

It is not a de Polignac number, because 668643337 - 2²³ = 660254729 is a prime.

It is a super-2 number, since 2×668643337² = 894167824228991138, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668643377) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19665964 + ... + 19665997.

It is an arithmetic number, because the mean of its divisors is an integer number (176993829).

Almost surely, 2^668643337 is an apocalyptic number.

It is an amenable number.

668643337 is a deficient number, since it is larger than the sum of its proper divisors (39331979).

668643337 is a wasteful number, since it uses less digits than its factorization.

668643337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39331978.

The product of its digits is 1306368, while the sum is 46.

The square root of 668643337 is about 25858.1386994501. The cubic root of 668643337 is about 874.4430031144.

The spelling of 668643337 in words is "six hundred sixty-eight million, six hundred forty-three thousand, three hundred thirty-seven".