21113311 has 8 divisors (see below), whose sum is σ = 21430640. Its totient is φ = 20798208.

The previous prime is 21113299. The next prime is 21113317. The reversal of 21113311 is 11331112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21113311 - 2⁹ = 21112799 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21113291 and 21113300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29425 + ... + 30133.

It is an arithmetic number, because the mean of its divisors is an integer number (2678830).

Almost surely, 2^21113311 is an apocalyptic number.

21113311 is a deficient number, since it is larger than the sum of its proper divisors (317329).

21113311 is an equidigital number, since it uses as much as digits as its factorization.

21113311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113.

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

The square root of 21113311 is about 4594.9223061984. The cubic root of 21113311 is about 276.3877444140.

Adding to 21113311 its reverse (11331112), we get a palindrome (32444423).

The spelling of 21113311 in words is "twenty-one million, one hundred thirteen thousand, three hundred eleven".