216981205 has 24 divisors (see below), whose sum is σ = 303432192. Its totient is φ = 145913664.

The previous prime is 216981203. The next prime is 216981211. The reversal of 216981205 is 502189612.

It is not a de Polignac number, because 216981205 - 2¹ = 216981203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216981203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97212 + ... + 99418.

It is an arithmetic number, because the mean of its divisors is an integer number (12643008).

Almost surely, 2^216981205 is an apocalyptic number.

It is an amenable number.

216981205 is a deficient number, since it is larger than the sum of its proper divisors (86450987).

216981205 is an equidigital number, since it uses as much as digits as its factorization.

216981205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2325 (or 2272 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 216981205 is about 14730.2819049738. The cubic root of 216981205 is about 600.9071509189.

The spelling of 216981205 in words is "two hundred sixteen million, nine hundred eighty-one thousand, two hundred five".