1216318011 has 4 divisors (see below), whose sum is σ = 1621757352. Its totient is φ = 810878672.

The previous prime is 1216318007. The next prime is 1216318021. The reversal of 1216318011 is 1108136121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1216318011 - 2² = 1216318007 is a prime.

It is a super-2 number, since 2×1216318011² = 2958859007765992242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216318001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202719666 + ... + 202719671.

It is an arithmetic number, because the mean of its divisors is an integer number (405439338).

Almost surely, 2^1216318011 is an apocalyptic number.

1216318011 is a deficient number, since it is larger than the sum of its proper divisors (405439341).

1216318011 is an equidigital number, since it uses as much as digits as its factorization.

1216318011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405439340.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 1216318011 is about 34875.7510456764. The cubic root of 1216318011 is about 1067.4536975494.

The spelling of 1216318011 in words is "one billion, two hundred sixteen million, three hundred eighteen thousand, eleven".