1216809824 has 48 divisors (see below), whose sum is σ = 2491675200. Its totient is φ = 584423424.

The previous prime is 1216809823. The next prime is 1216809851. The reversal of 1216809824 is 4289086121.

It is a super-2 number, since 2×1216809824² = 2961252295565821952, which contains 22 as substring.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216809823) 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 7 ways as a sum of consecutive naturals, for example, 87032 + ... + 100040.

It is an arithmetic number, because the mean of its divisors is an integer number (51909900).

Almost surely, 2^1216809824 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216809824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1245837600).

1216809824 is an abundant number, since it is smaller than the sum of its proper divisors (1274865376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216809824 is a wasteful number, since it uses less digits than its factorization.

1216809824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13135 (or 13127 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 1216809824 is about 34882.8012636600. The cubic root of 1216809824 is about 1067.5975516122.

The spelling of 1216809824 in words is "one billion, two hundred sixteen million, eight hundred nine thousand, eight hundred twenty-four".