1216813008 has 80 divisors (see below), whose sum is σ = 3236417856. Its totient is φ = 393768960.

The previous prime is 1216812937. The next prime is 1216813027. The reversal of 1216813008 is 8003186121.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 244303 + ... + 249233.

Almost surely, 2^1216813008 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 1216813008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1618208928).

1216813008 is an abundant number, since it is smaller than the sum of its proper divisors (2019604848).

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

1216813008 is a wasteful number, since it uses less digits than its factorization.

1216813008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5092 (or 5086 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1216813008 is about 34882.8469021667. The cubic root of 1216813008 is about 1067.5984827979.

Adding to 1216813008 its reverse (8003186121), we get a palindrome (9219999129).

The spelling of 1216813008 in words is "one billion, two hundred sixteen million, eight hundred thirteen thousand, eight".