229721 has 4 divisors (see below), whose sum is σ = 243252. Its totient is φ = 216192.

The previous prime is 229717. The next prime is 229727. The reversal of 229721 is 127922.

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 151321 + 78400 = 389^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 229721 - 2² = 229717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (229727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6740 + ... + 6773.

It is an arithmetic number, because the mean of its divisors is an integer number (60813).

2²²⁹⁷²¹ is an apocalyptic number.

It is an amenable number.

229721 is a deficient number, since it is larger than the sum of its proper divisors (13531).

229721 is a wasteful number, since it uses less digits than its factorization.

229721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13530.

The product of its digits is 504, while the sum is 23.

The square root of 229721 is about 479.2921864583. The cubic root of 229721 is about 61.2444726374.

The spelling of 229721 in words is "two hundred twenty-nine thousand, seven hundred twenty-one".