22217021 has 2 divisors, whose sum is σ = 22217022. Its totient is φ = 22217020.

The previous prime is 22217009. The next prime is 22217029. The reversal of 22217021 is 12071222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13980121 + 8236900 = 3739^2 + 2870^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22217021 is a prime.

It is a super-2 number, since 2×22217021² = 987192044228882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22217029) 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 as a sum of consecutive naturals, namely, 11108510 + 11108511.

It is an arithmetic number, because the mean of its divisors is an integer number (11108511).

Almost surely, 2^22217021 is an apocalyptic number.

It is an amenable number.

22217021 is a deficient number, since it is larger than the sum of its proper divisors (1).

22217021 is an equidigital number, since it uses as much as digits as its factorization.

22217021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 22217021 is about 4713.4935027005. The cubic root of 22217021 is about 281.1222856521.

Adding to 22217021 its reverse (12071222), we get a palindrome (34288243).

The spelling of 22217021 in words is "twenty-two million, two hundred seventeen thousand, twenty-one".