216096561 has 6 divisors (see below), whose sum is σ = 312139490. Its totient is φ = 144064368.

The previous prime is 216096547. The next prime is 216096581. The reversal of 216096561 is 165690612.

216096561 is a `hidden beast` number, since 2 + 1 + 6 + 0 + 96 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 216090000 + 6561 = 14700^2 + 81^2 .

It is not a de Polignac number, because 216096561 - 2²³ = 207707953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216096541) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12005356 + ... + 12005373.

Almost surely, 2^216096561 is an apocalyptic number.

It is an amenable number.

216096561 is a deficient number, since it is larger than the sum of its proper divisors (96042929).

216096561 is a wasteful number, since it uses less digits than its factorization.

216096561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24010735 (or 24010732 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 216096561 is about 14700.2231615714. The cubic root of 216096561 is about 600.0893950136.

It can be divided in two parts, 21609 and 6561, that multiplied together give a square (141776649 = 11907²).

The spelling of 216096561 in words is "two hundred sixteen million, ninety-six thousand, five hundred sixty-one".