1218399 has 16 divisors (see below), whose sum is σ = 1999872. Its totient is φ = 642528.

The previous prime is 1218391. The next prime is 1218401. The reversal of 1218399 is 9938121.

It is not a de Polignac number, because 1218399 - 2³ = 1218391 is a prime.

It is a super-2 number, since 2×1218399² = 2968992246402, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218391) 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 in 15 ways as a sum of consecutive naturals, for example, 1959 + ... + 2504.

It is an arithmetic number, because the mean of its divisors is an integer number (124992).

2^1218399 is an apocalyptic number.

1218399 is a deficient number, since it is larger than the sum of its proper divisors (781473).

1218399 is a wasteful number, since it uses less digits than its factorization.

1218399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4486.

The product of its digits is 3888, while the sum is 33.

The square root of 1218399 is about 1103.8111251478. The cubic root of 1218399 is about 106.8062116770.

The spelling of 1218399 in words is "one million, two hundred eighteen thousand, three hundred ninety-nine".