1218571121 has 2 divisors, whose sum is σ = 1218571122. Its totient is φ = 1218571120.

The previous prime is 1218571091. The next prime is 1218571139. The reversal of 1218571121 is 1211758121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 883278400 + 335292721 = 29720^2 + 18311^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218571121 - 2¹⁰ = 1218570097 is a prime.

It is not a weakly prime, because it can be changed into another prime (1218571171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609285560 + 609285561.

It is an arithmetic number, because the mean of its divisors is an integer number (609285561).

Almost surely, 2^1218571121 is an apocalyptic number.

It is an amenable number.

1218571121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218571121 is an equidigital number, since it uses as much as digits as its factorization.

1218571121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1120, while the sum is 29.

The square root of 1218571121 is about 34908.0380571581. The cubic root of 1218571121 is about 1068.1124087966.

The spelling of 1218571121 in words is "one billion, two hundred eighteen million, five hundred seventy-one thousand, one hundred twenty-one".