66613879 has 4 divisors (see below), whose sum is σ = 67608184. Its totient is φ = 65619576.

The previous prime is 66613861. The next prime is 66613901. The reversal of 66613879 is 97831666.

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 66613879 - 2⁵ = 66613847 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 (66613849) 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, 497052 + ... + 497185.

It is an arithmetic number, because the mean of its divisors is an integer number (16902046).

Almost surely, 2^66613879 is an apocalyptic number.

66613879 is a deficient number, since it is larger than the sum of its proper divisors (994305).

66613879 is an equidigital number, since it uses as much as digits as its factorization.

66613879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994304.

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

The square root of 66613879 is about 8161.7325979231. The cubic root of 66613879 is about 405.3730830281.

The spelling of 66613879 in words is "sixty-six million, six hundred thirteen thousand, eight hundred seventy-nine".