1216751328 has 192 divisors, whose sum is σ = 3850459200. Its totient is φ = 373800960.

The previous prime is 1216751321. The next prime is 1216751339. The reversal of 1216751328 is 8231576121.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1216751292 and 1216751301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216751321) 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 31 ways as a sum of consecutive naturals, for example, 1897888 + ... + 1898528.

It is an arithmetic number, because the mean of its divisors is an integer number (20054475).

Almost surely, 2^1216751328 is an apocalyptic number.

1216751328 is a gapful number since it is divisible by the number (18) 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 1216751328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1925229600).

1216751328 is an abundant number, since it is smaller than the sum of its proper divisors (2633707872).

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

1216751328 is an equidigital number, since it uses as much as digits as its factorization.

1216751328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699 (or 659 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 1216751328 is about 34881.9627888111. The cubic root of 1216751328 is about 1067.5804437109.

The spelling of 1216751328 in words is "one billion, two hundred sixteen million, seven hundred fifty-one thousand, three hundred twenty-eight".