21343231 has 8 divisors (see below), whose sum is σ = 26268704. Its totient is φ = 16886880.

The previous prime is 21343187. The next prime is 21343243. The reversal of 21343231 is 13234312.

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 21343231 - 2¹¹ = 21341183 is a prime.

It is a super-2 number, since 2×21343231² = 911067019038722, which contains 22 as substring.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 21343199 and 21343208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117180 + ... + 117361.

It is an arithmetic number, because the mean of its divisors is an integer number (3283588).

Almost surely, 2^21343231 is an apocalyptic number.

21343231 is a deficient number, since it is larger than the sum of its proper divisors (4925473).

21343231 is a wasteful number, since it uses less digits than its factorization.

21343231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234561.

The product of its digits is 432, while the sum is 19.

The square root of 21343231 is about 4619.8734831162. The cubic root of 21343231 is about 277.3873947261.

Adding to 21343231 its reverse (13234312), we get a palindrome (34577543).

The spelling of 21343231 in words is "twenty-one million, three hundred forty-three thousand, two hundred thirty-one".