216831889 has 4 divisors (see below), whose sum is σ = 229586724. Its totient is φ = 204077056.

The previous prime is 216831871. The next prime is 216831893. The reversal of 216831889 is 988138612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 130713489 + 86118400 = 11433^2 + 9280^2 .

It is a cyclic number.

It is not a de Polignac number, because 216831889 - 2⁷ = 216831761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216831809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6377392 + ... + 6377425.

It is an arithmetic number, because the mean of its divisors is an integer number (57396681).

Almost surely, 2^216831889 is an apocalyptic number.

It is an amenable number.

216831889 is a deficient number, since it is larger than the sum of its proper divisors (12754835).

216831889 is a wasteful number, since it uses less digits than its factorization.

216831889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12754834.

The product of its digits is 165888, while the sum is 46.

The square root of 216831889 is about 14725.2126979545. The cubic root of 216831889 is about 600.7692808494.

The spelling of 216831889 in words is "two hundred sixteen million, eight hundred thirty-one thousand, eight hundred eighty-nine".