18223681 has 8 divisors (see below), whose sum is σ = 21042560. Its totient is φ = 15458688.

The previous prime is 18223663. The next prime is 18223703. The reversal of 18223681 is 18632281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18223681 - 2¹¹ = 18221633 is a prime.

It is a super-2 number, since 2×18223681² = 664205098379522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18223631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12741 + ... + 14098.

It is an arithmetic number, because the mean of its divisors is an integer number (2630320).

Almost surely, 2^18223681 is an apocalyptic number.

It is an amenable number.

18223681 is a deficient number, since it is larger than the sum of its proper divisors (2818879).

18223681 is an equidigital number, since it uses as much as digits as its factorization.

18223681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26943.

The product of its digits is 4608, while the sum is 31.

The square root of 18223681 is about 4268.9203553123. The cubic root of 18223681 is about 263.1552476779.

The spelling of 18223681 in words is "eighteen million, two hundred twenty-three thousand, six hundred eighty-one".