22218257 has 2 divisors, whose sum is σ = 22218258. Its totient is φ = 22218256.

The previous prime is 22218223. The next prime is 22218271. The reversal of 22218257 is 75281222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14868736 + 7349521 = 3856^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 22218257 - 2¹⁰ = 22217233 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (22218557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11109128 + 11109129.

It is an arithmetic number, because the mean of its divisors is an integer number (11109129).

Almost surely, 2^22218257 is an apocalyptic number.

It is an amenable number.

22218257 is a deficient number, since it is larger than the sum of its proper divisors (1).

22218257 is an equidigital number, since it uses as much as digits as its factorization.

22218257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 29.

The square root of 22218257 is about 4713.6246138190. The cubic root of 22218257 is about 281.1274987828.

Adding to 22218257 its reverse (75281222), we get a palindrome (97499479).

The spelling of 22218257 in words is "twenty-two million, two hundred eighteen thousand, two hundred fifty-seven".