216305331 has 16 divisors (see below), whose sum is σ = 333134208. Its totient is φ = 123382400.

The previous prime is 216305281. The next prime is 216305347. The reversal of 216305331 is 133503612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 216305331 - 2⁷ = 216305203 is a prime.

It is a super-2 number, since 2×216305331² = 93575992438039122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216305371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192225 + ... + 193346.

It is an arithmetic number, because the mean of its divisors is an integer number (20820888).

Almost surely, 2^216305331 is an apocalyptic number.

216305331 is a deficient number, since it is larger than the sum of its proper divisors (116828877).

216305331 is a wasteful number, since it uses less digits than its factorization.

216305331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385602.

The product of its (nonzero) digits is 1620, while the sum is 24.

The square root of 216305331 is about 14707.3223599675. The cubic root of 216305331 is about 600.2825807815.

Adding to 216305331 its reverse (133503612), we get a palindrome (349808943).

The spelling of 216305331 in words is "two hundred sixteen million, three hundred five thousand, three hundred thirty-one".