21133411 has 4 divisors (see below), whose sum is σ = 22759072. Its totient is φ = 19507752.

The previous prime is 21133403. The next prime is 21133423. The reversal of 21133411 is 11433112.

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 21133411 - 2³ = 21133403 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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 812811 + ... + 812836.

It is an arithmetic number, because the mean of its divisors is an integer number (5689768).

Almost surely, 2^21133411 is an apocalyptic number.

21133411 is a deficient number, since it is larger than the sum of its proper divisors (1625661).

21133411 is a wasteful number, since it uses less digits than its factorization.

21133411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1625660.

The product of its digits is 72, while the sum is 16.

The square root of 21133411 is about 4597.1089828282. The cubic root of 21133411 is about 276.4754241984.

Adding to 21133411 its reverse (11433112), we get a palindrome (32566523).

The spelling of 21133411 in words is "twenty-one million, one hundred thirty-three thousand, four hundred eleven".