668032681 has 8 divisors (see below), whose sum is σ = 677916864. Its totient is φ = 658161840.

The previous prime is 668032657. The next prime is 668032691. The reversal of 668032681 is 186230866.

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

It is a cyclic number.

It is not a de Polignac number, because 668032681 - 2⁷ = 668032553 is a prime.

It is a super-2 number, since 2×668032681² = 892535325768095522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668032621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145635 + ... + 150151.

It is an arithmetic number, because the mean of its divisors is an integer number (84739608).

Almost surely, 2^668032681 is an apocalyptic number.

It is an amenable number.

668032681 is a deficient number, since it is larger than the sum of its proper divisors (9884183).

668032681 is a wasteful number, since it uses less digits than its factorization.

668032681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6671.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 668032681 is about 25846.3281918341. The cubic root of 668032681 is about 874.1767193934.

The spelling of 668032681 in words is "six hundred sixty-eight million, thirty-two thousand, six hundred eighty-one".