66613723 has 4 divisors (see below), whose sum is σ = 72669528. Its totient is φ = 60557920.

The previous prime is 66613721. The next prime is 66613759. The reversal of 66613723 is 32731666.

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 66613723 - 2¹ = 66613721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66613721) 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, 3027886 + ... + 3027907.

It is an arithmetic number, because the mean of its divisors is an integer number (18167382).

Almost surely, 2^66613723 is an apocalyptic number.

66613723 is a deficient number, since it is larger than the sum of its proper divisors (6055805).

66613723 is a wasteful number, since it uses less digits than its factorization.

66613723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6055804.

The product of its digits is 27216, while the sum is 34.

The square root of 66613723 is about 8161.7230411231. The cubic root of 66613723 is about 405.3727665863.

The spelling of 66613723 in words is "sixty-six million, six hundred thirteen thousand, seven hundred twenty-three".