1218537197 has 2 divisors, whose sum is σ = 1218537198. Its totient is φ = 1218537196.

The previous prime is 1218537163. The next prime is 1218537289. The reversal of 1218537197 is 7917358121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1069355401 + 149181796 = 32701^2 + 12214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218537197 - 2¹⁰ = 1218536173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218534197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609268598 + 609268599.

It is an arithmetic number, because the mean of its divisors is an integer number (609268599).

Almost surely, 2^1218537197 is an apocalyptic number.

It is an amenable number.

1218537197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218537197 is an equidigital number, since it uses as much as digits as its factorization.

1218537197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 44.

The square root of 1218537197 is about 34907.5521484965. The cubic root of 1218537197 is about 1068.1024969195.

The spelling of 1218537197 in words is "one billion, two hundred eighteen million, five hundred thirty-seven thousand, one hundred ninety-seven".