1216889511 has 16 divisors (see below), whose sum is σ = 1647153120. Its totient is φ = 799027200.

The previous prime is 1216889491. The next prime is 1216889533. The reversal of 1216889511 is 1159886121.

It is not a de Polignac number, because 1216889511 - 2⁷ = 1216889383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216884511) 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 in 15 ways as a sum of consecutive naturals, for example, 48075 + ... + 68883.

It is an arithmetic number, because the mean of its divisors is an integer number (102947070).

Almost surely, 2^1216889511 is an apocalyptic number.

1216889511 is a deficient number, since it is larger than the sum of its proper divisors (430263609).

1216889511 is a wasteful number, since it uses less digits than its factorization.

1216889511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21106.

The product of its digits is 34560, while the sum is 42.

The square root of 1216889511 is about 34883.9434554065. The cubic root of 1216889511 is about 1067.6208562095.

The spelling of 1216889511 in words is "one billion, two hundred sixteen million, eight hundred eighty-nine thousand, five hundred eleven".