66323399 has 4 divisors (see below), whose sum is σ = 66660264. Its totient is φ = 65986536.

The previous prime is 66323393. The next prime is 66323401. The reversal of 66323399 is 99332366.

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 66323399 - 2²⁴ = 49546183 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 (66323393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168137 + ... + 168530.

It is an arithmetic number, because the mean of its divisors is an integer number (16665066).

Almost surely, 2^66323399 is an apocalyptic number.

66323399 is a deficient number, since it is larger than the sum of its proper divisors (336865).

66323399 is a wasteful number, since it uses less digits than its factorization.

66323399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336864.

The product of its digits is 157464, while the sum is 41.

The square root of 66323399 is about 8143.9179146158. The cubic root of 66323399 is about 404.7829940435.

The spelling of 66323399 in words is "sixty-six million, three hundred twenty-three thousand, three hundred ninety-nine".