1211212117 has 2 divisors, whose sum is σ = 1211212118. Its totient is φ = 1211212116.

The previous prime is 1211212063. The next prime is 1211212151. The reversal of 1211212117 is 7112121121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1112289201 + 98922916 = 33351^2 + 9946^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211212117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211212094 and 1211212103.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211212187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605606058 + 605606059.

It is an arithmetic number, because the mean of its divisors is an integer number (605606059).

Almost surely, 2^1211212117 is an apocalyptic number.

It is an amenable number.

1211212117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211212117 is an equidigital number, since it uses as much as digits as its factorization.

1211212117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56, while the sum is 19.

The square root of 1211212117 is about 34802.4728575428. The cubic root of 1211212117 is about 1065.9579402179.

Adding to 1211212117 its reverse (7112121121), we get a palindrome (8323333238).

The spelling of 1211212117 in words is "one billion, two hundred eleven million, two hundred twelve thousand, one hundred seventeen".