1012121221 has 2 divisors, whose sum is σ = 1012121222. Its totient is φ = 1012121220.

The previous prime is 1012121207. The next prime is 1012121251. The reversal of 1012121221 is 1221212101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 823058721 + 189062500 = 28689^2 + 13750^2 .

It is a cyclic number.

It is not a de Polignac number, because 1012121221 - 2¹³ = 1012113029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1012121251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 506060610 + 506060611.

It is an arithmetic number, because the mean of its divisors is an integer number (506060611).

Almost surely, 2^1012121221 is an apocalyptic number.

It is an amenable number.

1012121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1012121221 is an equidigital number, since it uses as much as digits as its factorization.

1012121221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1012121221 is about 31813.8526588654. The cubic root of 1012121221 is about 1004.0241911627.

Adding to 1012121221 its reverse (1221212101), we get a palindrome (2233333322).

The spelling of 1012121221 in words is "one billion, twelve million, one hundred twenty-one thousand, two hundred twenty-one".