123121217 has 2 divisors, whose sum is σ = 123121218. Its totient is φ = 123121216.

The previous prime is 123121189. The next prime is 123121249. The reversal of 123121217 is 712121321.

It is a Cunningham number, because it is equal to 11096²+1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123121216 + 1 = 11096^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 123121217 - 2¹⁴ = 123104833 is a prime.

It is a super-2 number, since 2×123121217² = 30317668151122178, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123121417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61560608 + 61560609.

It is an arithmetic number, because the mean of its divisors is an integer number (61560609).

Almost surely, 2^123121217 is an apocalyptic number.

It is an amenable number.

123121217 is a deficient number, since it is larger than the sum of its proper divisors (1).

123121217 is an equidigital number, since it uses as much as digits as its factorization.

123121217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 168, while the sum is 20.

The square root of 123121217 is about 11096.0000450613. Note that the first 4 decimals coincide. The cubic root of 123121217 is about 497.4822996489.

Adding to 123121217 its reverse (712121321), we get a palindrome (835242538).

The spelling of 123121217 in words is "one hundred twenty-three million, one hundred twenty-one thousand, two hundred seventeen".