1121211122221 has 2 divisors, whose sum is σ = 1121211122222. Its totient is φ = 1121211122220.

The previous prime is 1121211122179. The next prime is 1121211122267. The reversal of 1121211122221 is 1222211121211.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1027210628196 + 94000494025 = 1013514^2 + 306595^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121211122221 - 2³¹ = 1119063638573 is a prime.

It is a super-2 number, since 2×1121211122221² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1121211122621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560605561110 + 560605561111.

It is an arithmetic number, because the mean of its divisors is an integer number (560605561111).

Almost surely, 2^{1121211122221} is an apocalyptic number.

It is an amenable number.

1121211122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121211122221 is an equidigital number, since it uses as much as digits as its factorization.

1121211122221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64, while the sum is 19.

Adding to 1121211122221 its reverse (1222211121211), we get a palindrome (2343422243432).

The spelling of 1121211122221 in words is "one trillion, one hundred twenty-one billion, two hundred eleven million, one hundred twenty-two thousand, two hundred twenty-one".