221116729 has 4 divisors (see below), whose sum is σ = 221743476. Its totient is φ = 220489984.

The previous prime is 221116723. The next prime is 221116741. The reversal of 221116729 is 927611122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28601104 + 192515625 = 5348^2 + 13875^2 .

It is a cyclic number.

It is not a de Polignac number, because 221116729 - 2⁵ = 221116697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221116729.

It is not an unprimeable number, because it can be changed into a prime (221116723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312844 + ... + 313549.

It is an arithmetic number, because the mean of its divisors is an integer number (55435869).

Almost surely, 2^221116729 is an apocalyptic number.

It is an amenable number.

221116729 is a deficient number, since it is larger than the sum of its proper divisors (626747).

221116729 is an equidigital number, since it uses as much as digits as its factorization.

221116729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626746.

The product of its digits is 3024, while the sum is 31.

The square root of 221116729 is about 14869.9942501670. The cubic root of 221116729 is about 604.7007868611.

The spelling of 221116729 in words is "two hundred twenty-one million, one hundred sixteen thousand, seven hundred twenty-nine".