66696947 has 4 divisors (see below), whose sum is σ = 67206216. Its totient is φ = 66187680.

The previous prime is 66696919. The next prime is 66696953. The reversal of 66696947 is 74969666.

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

It is a cyclic number.

It is not a de Polignac number, because 66696947 - 2¹² = 66692851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66696907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254438 + ... + 254699.

It is an arithmetic number, because the mean of its divisors is an integer number (16801554).

Almost surely, 2^66696947 is an apocalyptic number.

66696947 is a deficient number, since it is larger than the sum of its proper divisors (509269).

66696947 is a wasteful number, since it uses less digits than its factorization.

66696947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509268.

The product of its digits is 2939328, while the sum is 53.

The square root of 66696947 is about 8166.8198829165. The cubic root of 66696947 is about 405.5415141139.

The spelling of 66696947 in words is "sixty-six million, six hundred ninety-six thousand, nine hundred forty-seven".