66814679 has 4 divisors (see below), whose sum is σ = 66831384. Its totient is φ = 66797976.

The previous prime is 66814673. The next prime is 66814681. The reversal of 66814679 is 97641866.

It is a happy number.

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 66814679 - 2⁴ = 66814663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66814673) 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, 1604 + ... + 11670.

It is an arithmetic number, because the mean of its divisors is an integer number (16707846).

Almost surely, 2^66814679 is an apocalyptic number.

66814679 is a deficient number, since it is larger than the sum of its proper divisors (16705).

66814679 is a wasteful number, since it uses less digits than its factorization.

66814679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16704.

The product of its digits is 435456, while the sum is 47.

The square root of 66814679 is about 8174.0246512963. The cubic root of 66814679 is about 405.7799915369.

The spelling of 66814679 in words is "sixty-six million, eight hundred fourteen thousand, six hundred seventy-nine".