1216808559 has 24 divisors (see below), whose sum is σ = 1816743552. Its totient is φ = 783984960.

The previous prime is 1216808533. The next prime is 1216808569. The reversal of 1216808559 is 9558086121.

It is a happy number.

1216808559 is a `hidden beast` number, since 1 + 2 + 16 + 80 + 8 + 559 = 666.

It is not a de Polignac number, because 1216808559 - 2²⁸ = 948373103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216808569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 242197 + ... + 247169.

It is an arithmetic number, because the mean of its divisors is an integer number (75697648).

Almost surely, 2^1216808559 is an apocalyptic number.

1216808559 is a deficient number, since it is larger than the sum of its proper divisors (599934993).

1216808559 is a wasteful number, since it uses less digits than its factorization.

1216808559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5887 (or 5884 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 45.

The square root of 1216808559 is about 34882.7831315106. The cubic root of 1216808559 is about 1067.5971816526.

The spelling of 1216808559 in words is "one billion, two hundred sixteen million, eight hundred eight thousand, five hundred fifty-nine".