1222121521 has 2 divisors, whose sum is σ = 1222121522. Its totient is φ = 1222121520.

The previous prime is 1222121501. The next prime is 1222121539. The reversal of 1222121521 is 1251212221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 854977600 + 367143921 = 29240^2 + 19161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1222121521 - 2⁹ = 1222121009 is a prime.

It is not a weakly prime, because it can be changed into another prime (1222121501) 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, 611060760 + 611060761.

It is an arithmetic number, because the mean of its divisors is an integer number (611060761).

Almost surely, 2^1222121521 is an apocalyptic number.

It is an amenable number.

1222121521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1222121521 is an equidigital number, since it uses as much as digits as its factorization.

1222121521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 160, while the sum is 19.

The square root of 1222121521 is about 34958.8546866170. The cubic root of 1222121521 is about 1069.1487453169.

Adding to 1222121521 its reverse (1251212221), we get a palindrome (2473333742).

The spelling of 1222121521 in words is "one billion, two hundred twenty-two million, one hundred twenty-one thousand, five hundred twenty-one".