216726689561 has 8 divisors (see below), whose sum is σ = 216869775360. Its totient is φ = 216583649568.

The previous prime is 216726689521. The next prime is 216726689573. The reversal of 216726689561 is 165986627612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216726689561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 216726689561.

It is not an unprimeable number, because it can be changed into a prime (216726689521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16062560 + ... + 16076046.

It is an arithmetic number, because the mean of its divisors is an integer number (27108721920).

Almost surely, 2^216726689561 is an apocalyptic number.

It is an amenable number.

216726689561 is a deficient number, since it is larger than the sum of its proper divisors (143085799).

216726689561 is a wasteful number, since it uses less digits than its factorization.

216726689561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22903.

The product of its digits is 13063680, while the sum is 59.

The spelling of 216726689561 in words is "two hundred sixteen billion, seven hundred twenty-six million, six hundred eighty-nine thousand, five hundred sixty-one".