1216599888 has 160 divisors (see below), whose sum is σ = 3759759360. Its totient is φ = 331729920.

The previous prime is 1216599871. The next prime is 1216599893. The reversal of 1216599888 is 8889956121.

It is a super-2 number, since 2×1216599888² = 2960230574963225088, which contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 646533 + ... + 648411.

It is an arithmetic number, because the mean of its divisors is an integer number (23498496).

Almost surely, 2^1216599888 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 1216599888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1879879680).

1216599888 is an abundant number, since it is smaller than the sum of its proper divisors (2543159472).

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

1216599888 is a wasteful number, since it uses less digits than its factorization.

1216599888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1985 (or 1979 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 57.

The square root of 1216599888 is about 34879.7919718567. The cubic root of 1216599888 is about 1067.5361506039.

The spelling of 1216599888 in words is "one billion, two hundred sixteen million, five hundred ninety-nine thousand, eight hundred eighty-eight".