216528889 has 6 divisors (see below), whose sum is σ = 217531230. Its totient is φ = 215531136.

The previous prime is 216528863. The next prime is 216528919. The reversal of 216528889 is 988825612.

It can be written as a sum of positive squares in 3 ways, for example, as 141134400 + 75394489 = 11880^2 + 8683^2 .

It is not a de Polignac number, because 216528889 - 2⁵ = 216528857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216528839) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50377 + ... + 54505.

It is an arithmetic number, because the mean of its divisors is an integer number (36255205).

Almost surely, 2^216528889 is an apocalyptic number.

It is an amenable number.

216528889 is a deficient number, since it is larger than the sum of its proper divisors (1002341).

216528889 is an frugal number, since it uses more digits than its factorization.

216528889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4587 (or 4358 counting only the distinct ones).

The product of its digits is 552960, while the sum is 49.

The square root of 216528889 is about 14714.9206249983. The cubic root of 216528889 is about 600.4893128834.

The spelling of 216528889 in words is "two hundred sixteen million, five hundred twenty-eight thousand, eight hundred eighty-nine".