216942889 has 4 divisors (see below), whose sum is σ = 216972756. Its totient is φ = 216913024.

The previous prime is 216942883. The next prime is 216942907. The reversal of 216942889 is 988249612.

216942889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 98307225 + 118635664 = 9915^2 + 10892^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216942889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216942883) 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, 3777 + ... + 21169.

It is an arithmetic number, because the mean of its divisors is an integer number (54243189).

Almost surely, 2^216942889 is an apocalyptic number.

It is an amenable number.

216942889 is a deficient number, since it is larger than the sum of its proper divisors (29867).

216942889 is a wasteful number, since it uses less digits than its factorization.

216942889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29866.

The product of its digits is 497664, while the sum is 49.

The square root of 216942889 is about 14728.9812614451. The cubic root of 216942889 is about 600.8717780952.

The spelling of 216942889 in words is "two hundred sixteen million, nine hundred forty-two thousand, eight hundred eighty-nine".