667668551 has 8 divisors (see below), whose sum is σ = 735174144. Its totient is φ = 601297720.

The previous prime is 667668527. The next prime is 667668563. The reversal of 667668551 is 155866766.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667668551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 667668551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667668571) 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, 282455 + ... + 284808.

It is an arithmetic number, because the mean of its divisors is an integer number (91896768).

Almost surely, 2^667668551 is an apocalyptic number.

667668551 is a deficient number, since it is larger than the sum of its proper divisors (67505593).

667668551 is a wasteful number, since it uses less digits than its factorization.

667668551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567381.

The product of its digits is 1814400, while the sum is 50.

The square root of 667668551 is about 25839.2830976403. The cubic root of 667668551 is about 874.0178589910.

The spelling of 667668551 in words is "six hundred sixty-seven million, six hundred sixty-eight thousand, five hundred fifty-one".