216835891 has 2 divisors, whose sum is σ = 216835892. Its totient is φ = 216835890.

The previous prime is 216835859. The next prime is 216835933. The reversal of 216835891 is 198538612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216835891 - 2⁵ = 216835859 is a prime.

It is not a weakly prime, because it can be changed into another prime (216835811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108417945 + 108417946.

It is an arithmetic number, because the mean of its divisors is an integer number (108417946).

Almost surely, 2^216835891 is an apocalyptic number.

216835891 is a deficient number, since it is larger than the sum of its proper divisors (1).

216835891 is an equidigital number, since it uses as much as digits as its factorization.

216835891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 43.

The square root of 216835891 is about 14725.3485867059. The cubic root of 216835891 is about 600.7729768984.

The spelling of 216835891 in words is "two hundred sixteen million, eight hundred thirty-five thousand, eight hundred ninety-one".