21043411 has 4 divisors (see below), whose sum is σ = 21110112. Its totient is φ = 20976712.

The previous prime is 21043409. The next prime is 21043423. The reversal of 21043411 is 11434012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21043411 - 2¹ = 21043409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21043441) 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, 32875 + ... + 33508.

It is an arithmetic number, because the mean of its divisors is an integer number (5277528).

Almost surely, 2^21043411 is an apocalyptic number.

21043411 is a deficient number, since it is larger than the sum of its proper divisors (66701).

21043411 is an equidigital number, since it uses as much as digits as its factorization.

21043411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66700.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21043411 is about 4587.3097780725. The cubic root of 21043411 is about 276.0823941850.

Adding to 21043411 its reverse (11434012), we get a palindrome (32477423).

The spelling of 21043411 in words is "twenty-one million, forty-three thousand, four hundred eleven".