1218391579 has 2 divisors, whose sum is σ = 1218391580. Its totient is φ = 1218391578.

The previous prime is 1218391567. The next prime is 1218391589. The reversal of 1218391579 is 9751938121.

It is a strong prime.

It is an emirp because it is prime and its reverse (9751938121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1218391579 - 2⁹ = 1218391067 is a prime.

It is a super-2 number, since 2×1218391579² = 2968956079556226482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1218391519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609195789 + 609195790.

It is an arithmetic number, because the mean of its divisors is an integer number (609195790).

Almost surely, 2^1218391579 is an apocalyptic number.

1218391579 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218391579 is an equidigital number, since it uses as much as digits as its factorization.

1218391579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 46.

The square root of 1218391579 is about 34905.4663197614. The cubic root of 1218391579 is about 1068.0599483222.

The spelling of 1218391579 in words is "one billion, two hundred eighteen million, three hundred ninety-one thousand, five hundred seventy-nine".