1218667399 has 2 divisors, whose sum is σ = 1218667400. Its totient is φ = 1218667398.

The previous prime is 1218667301. The next prime is 1218667403. The reversal of 1218667399 is 9937668121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1218667399 - 2⁹ = 1218666887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218667199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609333699 + 609333700.

It is an arithmetic number, because the mean of its divisors is an integer number (609333700).

Almost surely, 2^1218667399 is an apocalyptic number.

1218667399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218667399 is an equidigital number, since it uses as much as digits as its factorization.

1218667399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 52.

The square root of 1218667399 is about 34909.4170532823. The cubic root of 1218667399 is about 1068.1405381952.

The spelling of 1218667399 in words is "one billion, two hundred eighteen million, six hundred sixty-seven thousand, three hundred ninety-nine".