223521 has 4 divisors (see below), whose sum is σ = 298032. Its totient is φ = 149012.

The previous prime is 223507. The next prime is 223529. The reversal of 223521 is 125322.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 223521 - 2⁹ = 223009 is a prime.

It is a D-number.

It is a nialpdrome in base 8.

It is a self number, because there is not a number n which added to its sum of digits gives 223521.

It is not an unprimeable number, because it can be changed into a prime (223529) 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, 37251 + ... + 37256.

It is an arithmetic number, because the mean of its divisors is an integer number (74508).

2²²³⁵²¹ is an apocalyptic number.

It is an amenable number.

223521 is a deficient number, since it is larger than the sum of its proper divisors (74511).

223521 is an equidigital number, since it uses as much as digits as its factorization.

223521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74510.

The product of its digits is 120, while the sum is 15.

The square root of 223521 is about 472.7800757223. The cubic root of 223521 is about 60.6884590764.

Adding to 223521 its reverse (125322), we get a palindrome (348843).

The spelling of 223521 in words is "two hundred twenty-three thousand, five hundred twenty-one".