66697667 has 4 divisors (see below), whose sum is σ = 66825720. Its totient is φ = 66569616.

The previous prime is 66697663. The next prime is 66697669. The reversal of 66697667 is 76679666.

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 66697667 - 2² = 66697663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66697661) 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 3 ways as a sum of consecutive naturals, for example, 63242 + ... + 64287.

It is an arithmetic number, because the mean of its divisors is an integer number (16706430).

Almost surely, 2^66697667 is an apocalyptic number.

66697667 is a deficient number, since it is larger than the sum of its proper divisors (128053).

66697667 is a wasteful number, since it uses less digits than its factorization.

66697667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128052.

The product of its digits is 3429216, while the sum is 53.

The square root of 66697667 is about 8166.8639636032. The cubic root of 66697667 is about 405.5429733953.

The spelling of 66697667 in words is "sixty-six million, six hundred ninety-seven thousand, six hundred sixty-seven".