21230233 has 4 divisors (see below), whose sum is σ = 21962340. Its totient is φ = 20498128.

The previous prime is 21230227. The next prime is 21230243. The reversal of 21230233 is 33203212.

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 8363664 + 12866569 = 2892^2 + 3587^2 .

It is not a de Polignac number, because 21230233 - 2¹³ = 21222041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21230203) 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, 366010 + ... + 366067.

It is an arithmetic number, because the mean of its divisors is an integer number (5490585).

Almost surely, 2^21230233 is an apocalyptic number.

It is an amenable number.

21230233 is a deficient number, since it is larger than the sum of its proper divisors (732107).

21230233 is an equidigital number, since it uses as much as digits as its factorization.

21230233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732106.

The product of its (nonzero) digits is 216, while the sum is 16.

The square root of 21230233 is about 4607.6276976336. The cubic root of 21230233 is about 276.8970019391.

Adding to 21230233 its reverse (33203212), we get a palindrome (54433445).

The spelling of 21230233 in words is "twenty-one million, two hundred thirty thousand, two hundred thirty-three".