66878679 has 24 divisors (see below), whose sum is σ = 104040048. Its totient is φ = 38102400.

The previous prime is 66878659. The next prime is 66878743. The reversal of 66878679 is 97687866.

It is not a de Polignac number, because 66878679 - 2⁷ = 66878551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66878659) 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 23 ways as a sum of consecutive naturals, for example, 87969 + ... + 88725.

It is an arithmetic number, because the mean of its divisors is an integer number (4335002).

Almost surely, 2^66878679 is an apocalyptic number.

66878679 is a deficient number, since it is larger than the sum of its proper divisors (37161369).

66878679 is a wasteful number, since it uses less digits than its factorization.

66878679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1375 (or 1368 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 57.

The square root of 66878679 is about 8177.9385544280. The cubic root of 66878679 is about 405.9095121367.

The spelling of 66878679 in words is "sixty-six million, eight hundred seventy-eight thousand, six hundred seventy-nine".