1218197 has 2 divisors, whose sum is σ = 1218198. Its totient is φ = 1218196.

The previous prime is 1218179. The next prime is 1218199. The reversal of 1218197 is 7918121.

Together with previous prime (1218179) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1062961 + 155236 = 1031^2 + 394^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218197 - 2⁸ = 1217941 is a prime.

Together with 1218199, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609098 + 609099.

It is an arithmetic number, because the mean of its divisors is an integer number (609099).

2^1218197 is an apocalyptic number.

It is an amenable number.

1218197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218197 is an equidigital number, since it uses as much as digits as its factorization.

1218197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 29.

The square root of 1218197 is about 1103.7196201935. The cubic root of 1218197 is about 106.8003088359.

The spelling of 1218197 in words is "one million, two hundred eighteen thousand, one hundred ninety-seven".