21234311 has 4 divisors (see below), whose sum is σ = 24267792. Its totient is φ = 18200832.

The previous prime is 21234307. The next prime is 21234347. The reversal of 21234311 is 11343212.

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 21234311 - 2² = 21234307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21234311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234361) 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, 1516730 + ... + 1516743.

It is an arithmetic number, because the mean of its divisors is an integer number (6066948).

Almost surely, 2^21234311 is an apocalyptic number.

21234311 is a deficient number, since it is larger than the sum of its proper divisors (3033481).

21234311 is an equidigital number, since it uses as much as digits as its factorization.

21234311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3033480.

The product of its digits is 144, while the sum is 17.

The square root of 21234311 is about 4608.0702034583. The cubic root of 21234311 is about 276.9147300171.

Adding to 21234311 its reverse (11343212), we get a palindrome (32577523).

The spelling of 21234311 in words is "twenty-one million, two hundred thirty-four thousand, three hundred eleven".