2212121521 has 2 divisors, whose sum is σ = 2212121522. Its totient is φ = 2212121520.

The previous prime is 2212121489. The next prime is 2212121533. The reversal of 2212121521 is 1251212122.

It is a happy number.

2212121521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1305810496 + 906311025 = 36136^2 + 30105^2 .

It is a cyclic number.

It is not a de Polignac number, because 2212121521 - 2⁵ = 2212121489 is a prime.

It is not a weakly prime, because it can be changed into another prime (2212121921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1106060760 + 1106060761.

It is an arithmetic number, because the mean of its divisors is an integer number (1106060761).

Almost surely, 2^2212121521 is an apocalyptic number.

It is an amenable number.

2212121521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2212121521 is an equidigital number, since it uses as much as digits as its factorization.

2212121521 is an evil number, because the sum of its binary digits is even.

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

The square root of 2212121521 is about 47033.1959471180. The cubic root of 2212121521 is about 1302.9757318006.

Adding to 2212121521 its reverse (1251212122), we get a palindrome (3463333643).

The spelling of 2212121521 in words is "two billion, two hundred twelve million, one hundred twenty-one thousand, five hundred twenty-one".