18223985 has 16 divisors (see below), whose sum is σ = 23696400. Its totient is φ = 13374720.

The previous prime is 18223969. The next prime is 18223987. The reversal of 18223985 is 58932281.

It can be written as a sum of positive squares in 8 ways, for example, as 7360369 + 10863616 = 2713^2 + 3296^2 .

It is not a de Polignac number, because 18223985 - 2⁴ = 18223969 is a prime.

It is a super-2 number, since 2×18223985² = 664227258560450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (18223987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10991 + ... + 12539.

It is an arithmetic number, because the mean of its divisors is an integer number (1481025).

Almost surely, 2^18223985 is an apocalyptic number.

It is an amenable number.

18223985 is a deficient number, since it is larger than the sum of its proper divisors (5472415).

18223985 is a wasteful number, since it uses less digits than its factorization.

18223985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1748.

The product of its digits is 34560, while the sum is 38.

The square root of 18223985 is about 4268.9559613564. The cubic root of 18223985 is about 263.1567109526.

The spelling of 18223985 in words is "eighteen million, two hundred twenty-three thousand, nine hundred eighty-five".