66723999 has 4 divisors (see below), whose sum is σ = 88965336. Its totient is φ = 44482664.

The previous prime is 66723961. The next prime is 66724033. The reversal of 66723999 is 99932766.

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 66723999 - 2⁷ = 66723871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66723499) 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, 11120664 + ... + 11120669.

It is an arithmetic number, because the mean of its divisors is an integer number (22241334).

Almost surely, 2^66723999 is an apocalyptic number.

66723999 is a deficient number, since it is larger than the sum of its proper divisors (22241337).

66723999 is a wasteful number, since it uses less digits than its factorization.

66723999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22241336.

The product of its digits is 1102248, while the sum is 51.

The square root of 66723999 is about 8168.4759288376. The cubic root of 66723999 is about 405.5963353446.

The spelling of 66723999 in words is "sixty-six million, seven hundred twenty-three thousand, nine hundred ninety-nine".