1218553313 has 4 divisors (see below), whose sum is σ = 1218630420. Its totient is φ = 1218476208.

The previous prime is 1218553309. The next prime is 1218553367. The reversal of 1218553313 is 3133558121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 620408464 + 598144849 = 24908^2 + 24457^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218553313 - 2² = 1218553309 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1218553313.

It is not an unprimeable number, because it can be changed into a prime (1218553613) 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 3 ways as a sum of consecutive naturals, for example, 5270 + ... + 49647.

It is an arithmetic number, because the mean of its divisors is an integer number (304657605).

Almost surely, 2^1218553313 is an apocalyptic number.

It is an amenable number.

1218553313 is a deficient number, since it is larger than the sum of its proper divisors (77107).

1218553313 is an equidigital number, since it uses as much as digits as its factorization.

1218553313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77106.

The product of its digits is 10800, while the sum is 32.

The square root of 1218553313 is about 34907.7829860334. The cubic root of 1218553313 is about 1068.1072056976.

The spelling of 1218553313 in words is "one billion, two hundred eighteen million, five hundred fifty-three thousand, three hundred thirteen".