21111313 has 4 divisors (see below), whose sum is σ = 21217600. Its totient is φ = 21005028.

The previous prime is 21111301. The next prime is 21111373. The reversal of 21111313 is 31311112.

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 21111313 - 2¹⁷ = 20980241 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111293 and 21111302.

It is not an unprimeable number, because it can be changed into a prime (21111373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52845 + ... + 53242.

It is an arithmetic number, because the mean of its divisors is an integer number (5304400).

Almost surely, 2^21111313 is an apocalyptic number.

It is an amenable number.

21111313 is a deficient number, since it is larger than the sum of its proper divisors (106287).

21111313 is a wasteful number, since it uses less digits than its factorization.

21111313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106286.

The product of its digits is 18, while the sum is 13.

The square root of 21111313 is about 4594.7048871500. The cubic root of 21111313 is about 276.3790257415.

Adding to 21111313 its reverse (31311112), we get a palindrome (52422425).

The spelling of 21111313 in words is "twenty-one million, one hundred eleven thousand, three hundred thirteen".