18213233 has 2 divisors, whose sum is σ = 18213234. Its totient is φ = 18213232.

The previous prime is 18213211. The next prime is 18213253. The reversal of 18213233 is 33231281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13667809 + 4545424 = 3697^2 + 2132^2 .

It is an emirp because it is prime and its reverse (33231281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18213233 - 2¹⁰ = 18212209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18213199 and 18213208.

It is not a weakly prime, because it can be changed into another prime (18213203) 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 as a sum of consecutive naturals, namely, 9106616 + 9106617.

It is an arithmetic number, because the mean of its divisors is an integer number (9106617).

Almost surely, 2^18213233 is an apocalyptic number.

It is an amenable number.

18213233 is a deficient number, since it is larger than the sum of its proper divisors (1).

18213233 is an equidigital number, since it uses as much as digits as its factorization.

18213233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 23.

The square root of 18213233 is about 4267.6964512486. The cubic root of 18213233 is about 263.1049473456.

The spelling of 18213233 in words is "eighteen million, two hundred thirteen thousand, two hundred thirty-three".