1218571217 has 2 divisors, whose sum is σ = 1218571218. Its totient is φ = 1218571216.

The previous prime is 1218571201. The next prime is 1218571241. The reversal of 1218571217 is 7121758121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 941814721 + 276756496 = 30689^2 + 16636^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218571217 - 2⁴ = 1218571201 is a prime.

It is a super-2 number, since 2×1218571217² = 2969831621801722178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1218571817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609285608 + 609285609.

It is an arithmetic number, because the mean of its divisors is an integer number (609285609).

Almost surely, 2^1218571217 is an apocalyptic number.

It is an amenable number.

1218571217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218571217 is an equidigital number, since it uses as much as digits as its factorization.

1218571217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7840, while the sum is 35.

The square root of 1218571217 is about 34908.0394321996. The cubic root of 1218571217 is about 1068.1124368455.

The spelling of 1218571217 in words is "one billion, two hundred eighteen million, five hundred seventy-one thousand, two hundred seventeen".