21033233 has 12 divisors (see below), whose sum is σ = 24118668. Its totient is φ = 18270720.

The previous prime is 21033223. The next prime is 21033239. The reversal of 21033233 is 33233012.

It can be written as a sum of positive squares in 6 ways, for example, as 7246864 + 13786369 = 2692^2 + 3713^2 .

It is not a de Polignac number, because 21033233 - 2⁶ = 21033169 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21033239) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 788 + ... + 6533.

It is an arithmetic number, because the mean of its divisors is an integer number (2009889).

Almost surely, 2^21033233 is an apocalyptic number.

It is an amenable number.

21033233 is a deficient number, since it is larger than the sum of its proper divisors (3085435).

21033233 is a wasteful number, since it uses less digits than its factorization.

21033233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7364 (or 7351 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 17.

The square root of 21033233 is about 4586.2002790982. The cubic root of 21033233 is about 276.0378763744.

Adding to 21033233 its reverse (33233012), we get a palindrome (54266245).

The spelling of 21033233 in words is "twenty-one million, thirty-three thousand, two hundred thirty-three".