66945879 has 64 divisors (see below), whose sum is σ = 133217280. Its totient is φ = 32088960.

The previous prime is 66945877. The next prime is 66945929. The reversal of 66945879 is 97854966.

It is not a de Polignac number, because 66945879 - 2¹ = 66945877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66945877) 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 63 ways as a sum of consecutive naturals, for example, 25789 + ... + 28265.

It is an arithmetic number, because the mean of its divisors is an integer number (2081520).

Almost surely, 2^66945879 is an apocalyptic number.

66945879 is a deficient number, since it is larger than the sum of its proper divisors (66271401).

66945879 is a wasteful number, since it uses less digits than its factorization.

66945879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2517 (or 2511 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The square root of 66945879 is about 8182.0461377335. The cubic root of 66945879 is about 406.0454198662.

The spelling of 66945879 in words is "sixty-six million, nine hundred forty-five thousand, eight hundred seventy-nine".