21434231 has 8 divisors (see below), whose sum is σ = 26380704. Its totient is φ = 16958880.

The previous prime is 21434227. The next prime is 21434233. The reversal of 21434231 is 13243412.

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 21434231 - 2² = 21434227 is a prime.

It is a super-2 number, since 2×21434231² = 918852517122722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117680 + ... + 117861.

It is an arithmetic number, because the mean of its divisors is an integer number (3297588).

Almost surely, 2^21434231 is an apocalyptic number.

21434231 is a deficient number, since it is larger than the sum of its proper divisors (4946473).

21434231 is a wasteful number, since it uses less digits than its factorization.

21434231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235561.

The product of its digits is 576, while the sum is 20.

The square root of 21434231 is about 4629.7117620863. The cubic root of 21434231 is about 277.7810630663.

Adding to 21434231 its reverse (13243412), we get a palindrome (34677643).

The spelling of 21434231 in words is "twenty-one million, four hundred thirty-four thousand, two hundred thirty-one".