21413311 has 4 divisors (see below), whose sum is σ = 21654000. Its totient is φ = 21172624.

The previous prime is 21413303. The next prime is 21413369. The reversal of 21413311 is 11331412.

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 21413311 - 2³ = 21413303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21413611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120211 + ... + 120388.

It is an arithmetic number, because the mean of its divisors is an integer number (5413500).

Almost surely, 2^21413311 is an apocalyptic number.

21413311 is a deficient number, since it is larger than the sum of its proper divisors (240689).

21413311 is an equidigital number, since it uses as much as digits as its factorization.

21413311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240688.

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

The square root of 21413311 is about 4627.4518906197. The cubic root of 21413311 is about 277.6906613867.

Adding to 21413311 its reverse (11331412), we get a palindrome (32744723).

The spelling of 21413311 in words is "twenty-one million, four hundred thirteen thousand, three hundred eleven".