18228311 has 4 divisors (see below), whose sum is σ = 18243624. Its totient is φ = 18213000.

The previous prime is 18228307. The next prime is 18228317. The reversal of 18228311 is 11382281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11382281 = 1163 ⋅9787.

It is a cyclic number.

It is not a de Polignac number, because 18228311 - 2² = 18228307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18228317) 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 3 ways as a sum of consecutive naturals, for example, 5705 + ... + 8306.

It is an arithmetic number, because the mean of its divisors is an integer number (4560906).

Almost surely, 2^18228311 is an apocalyptic number.

18228311 is a deficient number, since it is larger than the sum of its proper divisors (15313).

18228311 is a wasteful number, since it uses less digits than its factorization.

18228311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15312.

The product of its digits is 768, while the sum is 26.

The square root of 18228311 is about 4269.4626125544. The cubic root of 18228311 is about 263.1775319725.

The spelling of 18228311 in words is "eighteen million, two hundred twenty-eight thousand, three hundred eleven".