1216331128 has 16 divisors (see below), whose sum is σ = 2354189760. Its totient is φ = 588547200.

The previous prime is 1216331117. The next prime is 1216331177. The reversal of 1216331128 is 8211336121.

It is a happy number.

It is a super-2 number, since 2×1216331128² = 2958922825883504768, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1216331096 and 1216331105.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2452033 + ... + 2452528.

It is an arithmetic number, because the mean of its divisors is an integer number (147136860).

Almost surely, 2^1216331128 is an apocalyptic number.

It is an amenable number.

1216331128 is a deficient number, since it is larger than the sum of its proper divisors (1137858632).

1216331128 is a wasteful number, since it uses less digits than its factorization.

1216331128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4904598 (or 4904594 counting only the distinct ones).

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

The square root of 1216331128 is about 34875.9390984673. The cubic root of 1216331128 is about 1067.4575347421.

Adding to 1216331128 its reverse (8211336121), we get a palindrome (9427667249).

The spelling of 1216331128 in words is "one billion, two hundred sixteen million, three hundred thirty-one thousand, one hundred twenty-eight".