121718917 has 2 divisors, whose sum is σ = 121718918. Its totient is φ = 121718916.

The previous prime is 121718903. The next prime is 121718923. The reversal of 121718917 is 719817121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90649441 + 31069476 = 9521^2 + 5574^2 .

It is a cyclic number.

It is not a de Polignac number, because 121718917 - 2²³ = 113330309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121718957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60859458 + 60859459.

It is an arithmetic number, because the mean of its divisors is an integer number (60859459).

Almost surely, 2^121718917 is an apocalyptic number.

It is an amenable number.

121718917 is a deficient number, since it is larger than the sum of its proper divisors (1).

121718917 is an equidigital number, since it uses as much as digits as its factorization.

121718917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 37.

The square root of 121718917 is about 11032.6296502692. The cubic root of 121718917 is about 495.5863771706.

The spelling of 121718917 in words is "one hundred twenty-one million, seven hundred eighteen thousand, nine hundred seventeen".