22251251221 has 2 divisors, whose sum is σ = 22251251222. Its totient is φ = 22251251220.

The previous prime is 22251251213. The next prime is 22251251287. The reversal of 22251251221 is 12215215222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17137428100 + 5113823121 = 130910^2 + 71511^2 .

It is a cyclic number.

It is not a de Polignac number, because 22251251221 - 2³ = 22251251213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22251251621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11125625610 + 11125625611.

It is an arithmetic number, because the mean of its divisors is an integer number (11125625611).

Almost surely, 2^22251251221 is an apocalyptic number.

It is an amenable number.

22251251221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22251251221 is an equidigital number, since it uses as much as digits as its factorization.

22251251221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1600, while the sum is 25.

Adding to 22251251221 its reverse (12215215222), we get a palindrome (34466466443).

The spelling of 22251251221 in words is "twenty-two billion, two hundred fifty-one million, two hundred fifty-one thousand, two hundred twenty-one".