223921 has 2 divisors, whose sum is σ = 223922. Its totient is φ = 223920.

The previous prime is 223919. The next prime is 223939. The reversal of 223921 is 129322.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211600 + 12321 = 460^2 + 111^2 .

It is a cyclic number.

It is not a de Polignac number, because 223921 - 2¹ = 223919 is a prime.

It is a super-2 number, since 2×223921² = 100281228482, which contains 22 as substring.

Together with 223919, it forms a pair of twin primes.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (223621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111960 + 111961.

It is an arithmetic number, because the mean of its divisors is an integer number (111961).

2²²³⁹²¹ is an apocalyptic number.

It is an amenable number.

223921 is a deficient number, since it is larger than the sum of its proper divisors (1).

223921 is an equidigital number, since it uses as much as digits as its factorization.

223921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 223921 is about 473.2029163055. The cubic root of 223921 is about 60.7246389990.

The spelling of 223921 in words is "two hundred twenty-three thousand, nine hundred twenty-one".