1218923 has 2 divisors, whose sum is σ = 1218924. Its totient is φ = 1218922.

The previous prime is 1218913. The next prime is 1218941. The reversal of 1218923 is 3298121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1218923 - 2⁶ = 1218859 is a prime.

It is a Sophie Germain prime.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 1218892 and 1218901.

It is not a weakly prime, because it can be changed into another prime (1218913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609461 + 609462.

It is an arithmetic number, because the mean of its divisors is an integer number (609462).

2^1218923 is an apocalyptic number.

1218923 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218923 is an equidigital number, since it uses as much as digits as its factorization.

1218923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 26.

The square root of 1218923 is about 1104.0484590814. The cubic root of 1218923 is about 106.8215209568.

The spelling of 1218923 in words is "one million, two hundred eighteen thousand, nine hundred twenty-three".