216209889 has 12 divisors (see below), whose sum is σ = 356918016. Its totient is φ = 123548472.

The previous prime is 216209887. The next prime is 216209897. The reversal of 216209889 is 988902612.

216209889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 216209889 - 2¹ = 216209887 is a prime.

It is a super-2 number, since 2×216209889² = 93493432202784642, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216209887) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1715889 + ... + 1716014.

It is an arithmetic number, because the mean of its divisors is an integer number (29743168).

Almost surely, 2^216209889 is an apocalyptic number.

It is an amenable number.

216209889 is a deficient number, since it is larger than the sum of its proper divisors (140708127).

216209889 is a wasteful number, since it uses less digits than its factorization.

216209889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3431916 (or 3431913 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 216209889 is about 14704.0772916902. The cubic root of 216209889 is about 600.1942787528.

The spelling of 216209889 in words is "two hundred sixteen million, two hundred nine thousand, eight hundred eighty-nine".