1218913 has 2 divisors, whose sum is σ = 1218914. Its totient is φ = 1218912.

The previous prime is 1218911. The next prime is 1218923. The reversal of 1218913 is 3198121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1216609 + 2304 = 1103^2 + 48^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218913 - 2¹ = 1218911 is a prime.

Together with 1218911, it forms a pair of twin primes.

1218913 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1218911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609456 + 609457.

It is an arithmetic number, because the mean of its divisors is an integer number (609457).

2^1218913 is an apocalyptic number.

It is an amenable number.

1218913 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218913 is an equidigital number, since it uses as much as digits as its factorization.

1218913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 25.

The square root of 1218913 is about 1104.0439302854. The cubic root of 1218913 is about 106.8212288361.

The spelling of 1218913 in words is "one million, two hundred eighteen thousand, nine hundred thirteen".