18228751 has 4 divisors (see below), whose sum is σ = 18293904. Its totient is φ = 18163600.

The previous prime is 18228703. The next prime is 18228797. The reversal of 18228751 is 15782281.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18228751 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 (18228701) 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, 32155 + ... + 32716.

It is an arithmetic number, because the mean of its divisors is an integer number (4573476).

Almost surely, 2^18228751 is an apocalyptic number.

18228751 is a deficient number, since it is larger than the sum of its proper divisors (65153).

18228751 is an equidigital number, since it uses as much as digits as its factorization.

18228751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65152.

The product of its digits is 8960, while the sum is 34.

The square root of 18228751 is about 4269.5141409767. The cubic root of 18228751 is about 263.1796495061.

The spelling of 18228751 in words is "eighteen million, two hundred twenty-eight thousand, seven hundred fifty-one".