66813679 has 2 divisors, whose sum is σ = 66813680. Its totient is φ = 66813678.

The previous prime is 66813661. The next prime is 66813707. The reversal of 66813679 is 97631866.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66813679 - 2⁵ = 66813647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66813619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33406839 + 33406840.

It is an arithmetic number, because the mean of its divisors is an integer number (33406840).

Almost surely, 2^66813679 is an apocalyptic number.

66813679 is a deficient number, since it is larger than the sum of its proper divisors (1).

66813679 is an equidigital number, since it uses as much as digits as its factorization.

66813679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 66813679 is about 8173.9634816899. The cubic root of 66813679 is about 405.7779671214. Note that the first 3 decimals are identical.

The spelling of 66813679 in words is "sixty-six million, eight hundred thirteen thousand, six hundred seventy-nine".