21434311 has 4 divisors (see below), whose sum is σ = 21443800. Its totient is φ = 21424824.

The previous prime is 21434293. The next prime is 21434323. The reversal of 21434311 is 11343412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21434311 - 2⁵ = 21434279 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 (21434341) 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, 820 + ... + 6598.

It is an arithmetic number, because the mean of its divisors is an integer number (5360950).

Almost surely, 2^21434311 is an apocalyptic number.

21434311 is a deficient number, since it is larger than the sum of its proper divisors (9489).

21434311 is an equidigital number, since it uses as much as digits as its factorization.

21434311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9488.

The product of its digits is 288, while the sum is 19.

The square root of 21434311 is about 4629.7204019249. The cubic root of 21434311 is about 277.7814086577.

Adding to 21434311 its reverse (11343412), we get a palindrome (32777723).

The spelling of 21434311 in words is "twenty-one million, four hundred thirty-four thousand, three hundred eleven".