18666713 has 4 divisors (see below), whose sum is σ = 20102628. Its totient is φ = 17230800.

The previous prime is 18666709. The next prime is 18666733. The reversal of 18666713 is 31766681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31766681 = 89 ⋅356929.

It can be written as a sum of positive squares in 2 ways, for example, as 1261129 + 17405584 = 1123^2 + 4172^2 .

It is a cyclic number.

It is not a de Polignac number, because 18666713 - 2² = 18666709 is a prime.

It is a Curzon 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, 717938 + ... + 717963.

It is an arithmetic number, because the mean of its divisors is an integer number (5025657).

Almost surely, 2^18666713 is an apocalyptic number.

18666713 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18666713 is a deficient number, since it is larger than the sum of its proper divisors (1435915).

18666713 is a wasteful number, since it uses less digits than its factorization.

18666713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1435914.

The product of its digits is 36288, while the sum is 38.

The square root of 18666713 is about 4320.4991609767. The cubic root of 18666713 is about 265.2707000060.

The spelling of 18666713 in words is "eighteen million, six hundred sixty-six thousand, seven hundred thirteen".