1218540769 has 2 divisors, whose sum is σ = 1218540770. Its totient is φ = 1218540768.

The previous prime is 1218540749. The next prime is 1218540781. The reversal of 1218540769 is 9670458121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624400144 + 594140625 = 24988^2 + 24375^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1218540769 is a prime.

It is a super-2 number, since 2×1218540769² = 2969683211430222722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1218540749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609270384 + 609270385.

It is an arithmetic number, because the mean of its divisors is an integer number (609270385).

Almost surely, 2^1218540769 is an apocalyptic number.

It is an amenable number.

1218540769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218540769 is an equidigital number, since it uses as much as digits as its factorization.

1218540769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 43.

The square root of 1218540769 is about 34907.6033121726. The cubic root of 1218540769 is about 1068.1035405912.

The spelling of 1218540769 in words is "one billion, two hundred eighteen million, five hundred forty thousand, seven hundred sixty-nine".