216813128 has 16 divisors (see below), whose sum is σ = 464599680. Its totient is φ = 92919888.

The previous prime is 216813119. The next prime is 216813133. The reversal of 216813128 is 821318612.

It is a junction number, because it is equal to n+sod(n) for n = 216813094 and 216813103.

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 3 ways as a sum of consecutive naturals, for example, 1935776 + ... + 1935887.

It is an arithmetic number, because the mean of its divisors is an integer number (29037480).

Almost surely, 2^216813128 is an apocalyptic number.

216813128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

216813128 is an abundant number, since it is smaller than the sum of its proper divisors (247786552).

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

216813128 is a wasteful number, since it uses less digits than its factorization.

216813128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3871676 (or 3871672 counting only the distinct ones).

The product of its digits is 4608, while the sum is 32.

The square root of 216813128 is about 14724.5756475357. The cubic root of 216813128 is about 600.7519535125.

The spelling of 216813128 in words is "two hundred sixteen million, eight hundred thirteen thousand, one hundred twenty-eight".