1216550011 has 4 divisors (see below), whose sum is σ = 1224013672. Its totient is φ = 1209086352.

The previous prime is 1216549979. The next prime is 1216550033. The reversal of 1216550011 is 1100556121.

It is a happy number.

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 1216550011 - 2⁵ = 1216549979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216550911) 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, 3731586 + ... + 3731911.

It is an arithmetic number, because the mean of its divisors is an integer number (306003418).

Almost surely, 2^1216550011 is an apocalyptic number.

1216550011 is a deficient number, since it is larger than the sum of its proper divisors (7463661).

1216550011 is an equidigital number, since it uses as much as digits as its factorization.

1216550011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7463660.

The product of its (nonzero) digits is 300, while the sum is 22.

The square root of 1216550011 is about 34879.0769803331. The cubic root of 1216550011 is about 1067.5215617954.

The spelling of 1216550011 in words is "one billion, two hundred sixteen million, five hundred fifty thousand, eleven".