1212220111217 has 2 divisors, whose sum is σ = 1212220111218. Its totient is φ = 1212220111216.

The previous prime is 1212220111213. The next prime is 1212220111229. The reversal of 1212220111217 is 7121110222121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1173515057521 + 38705053696 = 1083289^2 + 196736^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212220111217 - 2² = 1212220111213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212220111192 and 1212220111201.

It is not a weakly prime, because it can be changed into another prime (1212220111213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606110055608 + 606110055609.

It is an arithmetic number, because the mean of its divisors is an integer number (606110055609).

Almost surely, 2^{1212220111217} is an apocalyptic number.

It is an amenable number.

1212220111217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212220111217 is an equidigital number, since it uses as much as digits as its factorization.

1212220111217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 23.

Adding to 1212220111217 its reverse (7121110222121), we get a palindrome (8333330333338).

The spelling of 1212220111217 in words is "one trillion, two hundred twelve billion, two hundred twenty million, one hundred eleven thousand, two hundred seventeen".