66416691 has 16 divisors (see below), whose sum is σ = 97567488. Its totient is φ = 39852000.

The previous prime is 66416689. The next prime is 66416729. The reversal of 66416691 is 19661466.

It is not a de Polignac number, because 66416691 - 2¹ = 66416689 is a prime.

It is a super-2 number, since 2×66416691² = 8822353686778962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66416891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6631 + ... + 13296.

It is an arithmetic number, because the mean of its divisors is an integer number (6097968).

Almost surely, 2^66416691 is an apocalyptic number.

66416691 is a deficient number, since it is larger than the sum of its proper divisors (31150797).

66416691 is a wasteful number, since it uses less digits than its factorization.

66416691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20042.

The product of its digits is 46656, while the sum is 39.

The square root of 66416691 is about 8149.6436118397. The cubic root of 66416691 is about 404.9726974431.

The spelling of 66416691 in words is "sixty-six million, four hundred sixteen thousand, six hundred ninety-one".