216959664321 has 16 divisors (see below), whose sum is σ = 323053315200. Its totient is φ = 143905560624.

The previous prime is 216959664283. The next prime is 216959664331. The reversal of 216959664321 is 123466959612.

216959664321 is a `hidden beast` number, since 2 + 1 + 6 + 9 + 596 + 6 + 43 + 2 + 1 = 666.

It is not a de Polignac number, because 216959664321 - 2¹³ = 216959656129 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216959664331) 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, 20389461 + ... + 20400098.

It is an arithmetic number, because the mean of its divisors is an integer number (20190832200).

Almost surely, 2^216959664321 is an apocalyptic number.

It is an amenable number.

216959664321 is a deficient number, since it is larger than the sum of its proper divisors (106093650879).

216959664321 is a wasteful number, since it uses less digits than its factorization.

216959664321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40789765 (or 40789759 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 54.

The spelling of 216959664321 in words is "two hundred sixteen billion, nine hundred fifty-nine million, six hundred sixty-four thousand, three hundred twenty-one".