18666723 has 4 divisors (see below), whose sum is σ = 24888968. Its totient is φ = 12444480.

The previous prime is 18666709. The next prime is 18666733. The reversal of 18666723 is 32766681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32766681 = 3 ⋅10922227.

It is not a de Polignac number, because 18666723 - 2⁴ = 18666707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18666733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3111118 + ... + 3111123.

It is an arithmetic number, because the mean of its divisors is an integer number (6222242).

Almost surely, 2^18666723 is an apocalyptic number.

18666723 is a deficient number, since it is larger than the sum of its proper divisors (6222245).

18666723 is an equidigital number, since it uses as much as digits as its factorization.

18666723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6222244.

The product of its digits is 72576, while the sum is 39.

The square root of 18666723 is about 4320.5003182502. The cubic root of 18666723 is about 265.2707473756.

The spelling of 18666723 in words is "eighteen million, six hundred sixty-six thousand, seven hundred twenty-three".