67666491 has 6 divisors (see below), whose sum is σ = 97740500. Its totient is φ = 45110988.

The previous prime is 67666463. The next prime is 67666493. The reversal of 67666491 is 19466676.

It is a happy number.

It is not a de Polignac number, because 67666491 - 2⁷ = 67666363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67666493) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3759241 + ... + 3759258.

Almost surely, 2^67666491 is an apocalyptic number.

67666491 is a deficient number, since it is larger than the sum of its proper divisors (30074009).

67666491 is a wasteful number, since it uses less digits than its factorization.

67666491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7518505 (or 7518502 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 67666491 is about 8225.9644419363. The cubic root of 67666491 is about 407.4971277101.

The spelling of 67666491 in words is "sixty-seven million, six hundred sixty-six thousand, four hundred ninety-one".