1217917 has 2 divisors, whose sum is σ = 1217918. Its totient is φ = 1217916.

The previous prime is 1217903. The next prime is 1217921. The reversal of 1217917 is 7197121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 729316 + 488601 = 854^2 + 699^2 .

It is a cyclic number.

It is not a de Polignac number, because 1217917 - 2¹⁹ = 693629 is a prime.

1217917 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1217927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608958 + 608959.

It is an arithmetic number, because the mean of its divisors is an integer number (608959).

2^1217917 is an apocalyptic number.

It is an amenable number.

1217917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1217917 is an equidigital number, since it uses as much as digits as its factorization.

1217917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 882, while the sum is 28.

The square root of 1217917 is about 1103.5927690956. The cubic root of 1217917 is about 106.7921256007.

The spelling of 1217917 in words is "one million, two hundred seventeen thousand, nine hundred seventeen".