220609729 has 4 divisors (see below), whose sum is σ = 223088580. Its totient is φ = 218130880.

The previous prime is 220609717. The next prime is 220609747. The reversal of 220609729 is 927906022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 927906022 = 2 ⋅463953011.

It can be written as a sum of positive squares in 2 ways, for example, as 26286129 + 194323600 = 5127^2 + 13940^2 .

It is a cyclic number.

It is not a de Polignac number, because 220609729 - 2¹⁹ = 220085441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220609789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1239292 + ... + 1239469.

It is an arithmetic number, because the mean of its divisors is an integer number (55772145).

Almost surely, 2^220609729 is an apocalyptic number.

It is an amenable number.

220609729 is a deficient number, since it is larger than the sum of its proper divisors (2478851).

220609729 is an equidigital number, since it uses as much as digits as its factorization.

220609729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2478850.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 220609729 is about 14852.9367129871. The cubic root of 220609729 is about 604.2382590347.

The spelling of 220609729 in words is "two hundred twenty million, six hundred nine thousand, seven hundred twenty-nine".