1220211011221 has 2 divisors, whose sum is σ = 1220211011222. Its totient is φ = 1220211011220.

The previous prime is 1220211011191. The next prime is 1220211011231. The reversal of 1220211011221 is 1221101120221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1161137708721 + 59073302500 = 1077561^2 + 243050^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220211011221 - 2²¹ = 1220208914069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1220211011195 and 1220211011204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220211011231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610105505610 + 610105505611.

It is an arithmetic number, because the mean of its divisors is an integer number (610105505611).

Almost surely, 2^{1220211011221} is an apocalyptic number.

It is an amenable number.

1220211011221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220211011221 is an equidigital number, since it uses as much as digits as its factorization.

1220211011221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1220211011221 its reverse (1221101120221), we get a palindrome (2441312131442).

The spelling of 1220211011221 in words is "one trillion, two hundred twenty billion, two hundred eleven million, eleven thousand, two hundred twenty-one".