21133441 has 4 divisors (see below), whose sum is σ = 24152512. Its totient is φ = 18114372.

The previous prime is 21133433. The next prime is 21133451. The reversal of 21133441 is 14433112.

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 21133441 - 2³ = 21133433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21133451) 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, 1509525 + ... + 1509538.

It is an arithmetic number, because the mean of its divisors is an integer number (6038128).

Almost surely, 2^21133441 is an apocalyptic number.

It is an amenable number.

21133441 is a deficient number, since it is larger than the sum of its proper divisors (3019071).

21133441 is an equidigital number, since it uses as much as digits as its factorization.

21133441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019070.

The product of its digits is 288, while the sum is 19.

The square root of 21133441 is about 4597.1122457473. The cubic root of 21133441 is about 276.4755550222.

Adding to 21133441 its reverse (14433112), we get a palindrome (35566553).

The spelling of 21133441 in words is "twenty-one million, one hundred thirty-three thousand, four hundred forty-one".