223440021 has 48 divisors (see below), whose sum is σ = 383385600. Its totient is φ = 122749344.

The previous prime is 223440001. The next prime is 223440043. The reversal of 223440021 is 120044322.

223440021 is a `hidden beast` number, since 223 + 440 + 0 + 2 + 1 = 666.

223440021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 223440021 - 2⁵ = 223439989 is a prime.

It is a super-3 number, since 3×223440021³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 223439976 and 223440003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (223440001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 174060 + ... + 175338.

It is an arithmetic number, because the mean of its divisors is an integer number (7987200).

Almost surely, 2^223440021 is an apocalyptic number.

223440021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

223440021 is a deficient number, since it is larger than the sum of its proper divisors (159945579).

223440021 is a wasteful number, since it uses less digits than its factorization.

223440021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398 (or 1395 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 223440021 is about 14947.9102552832. The cubic root of 223440021 is about 606.8112928883.

Adding to 223440021 its reverse (120044322), we get a palindrome (343484343).

The spelling of 223440021 in words is "two hundred twenty-three million, four hundred forty thousand, twenty-one".