2121111217 has 2 divisors, whose sum is σ = 2121111218. Its totient is φ = 2121111216.

The previous prime is 2121111193. The next prime is 2121111229. The reversal of 2121111217 is 7121111212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1339852816 + 781258401 = 36604^2 + 27951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121111217 is a prime.

It is a super-2 number, since 2×2121111217² = 8998225589766442178, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2121111194 and 2121111203.

It is not a weakly prime, because it can be changed into another prime (2121111257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060555608 + 1060555609.

It is an arithmetic number, because the mean of its divisors is an integer number (1060555609).

Almost surely, 2^2121111217 is an apocalyptic number.

It is an amenable number.

2121111217 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121111217 is an equidigital number, since it uses as much as digits as its factorization.

2121111217 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2121111217 is about 46055.5231975493. The cubic root of 2121111217 is about 1284.8560689069.

Adding to 2121111217 its reverse (7121111212), we get a palindrome (9242222429).

The spelling of 2121111217 in words is "two billion, one hundred twenty-one million, one hundred eleven thousand, two hundred seventeen".