22018231 has 4 divisors (see below), whose sum is σ = 22486752. Its totient is φ = 21549712.

The previous prime is 22018223. The next prime is 22018237. The reversal of 22018231 is 13281022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13281022 = 2 ⋅6640511.

It is a cyclic number.

It is not a de Polignac number, because 22018231 - 2³ = 22018223 is a prime.

It is a super-2 number, since 2×22018231² = 969604992738722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22018199 and 22018208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22018237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234190 + ... + 234283.

It is an arithmetic number, because the mean of its divisors is an integer number (5621688).

Almost surely, 2^22018231 is an apocalyptic number.

22018231 is a deficient number, since it is larger than the sum of its proper divisors (468521).

22018231 is an equidigital number, since it uses as much as digits as its factorization.

22018231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468520.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 22018231 is about 4692.3587884986. The cubic root of 22018231 is about 280.2813116636.

Adding to 22018231 its reverse (13281022), we get a palindrome (35299253).

The spelling of 22018231 in words is "twenty-two million, eighteen thousand, two hundred thirty-one".