1216109440 has 384 divisors, whose sum is σ = 3858170400. Its totient is φ = 362299392.

The previous prime is 1216109437. The next prime is 1216109473. The reversal of 1216109440 is 449016121.

It is a super-2 number, since 2×1216109440² = 2957844340114227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 1216109399 and 1216109408.

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 47 ways as a sum of consecutive naturals, for example, 7745842 + ... + 7745998.

Almost surely, 2^1216109440 is an apocalyptic number.

1216109440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216109440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1929085200).

1216109440 is an abundant number, since it is smaller than the sum of its proper divisors (2642060960).

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

1216109440 is a wasteful number, since it uses less digits than its factorization.

1216109440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 1216109440 is about 34872.7607166396. The cubic root of 1216109440 is about 1067.3926793480.

The spelling of 1216109440 in words is "one billion, two hundred sixteen million, one hundred nine thousand, four hundred forty".