21343442231 has 4 divisors (see below), whose sum is σ = 21351837792. Its totient is φ = 21335046672.

The previous prime is 21343442209. The next prime is 21343442269. The reversal of 21343442231 is 13224434312.

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 21343442231 - 2⁶ = 21343442167 is a prime.

It is a super-2 number, since 2×21343442231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21343442194 and 21343442203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343442431) 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, 4193966 + ... + 4199051.

It is an arithmetic number, because the mean of its divisors is an integer number (5337959448).

Almost surely, 2^21343442231 is an apocalyptic number.

21343442231 is a deficient number, since it is larger than the sum of its proper divisors (8395561).

21343442231 is an equidigital number, since it uses as much as digits as its factorization.

21343442231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8395560.

The product of its digits is 13824, while the sum is 29.

Adding to 21343442231 its reverse (13224434312), we get a palindrome (34567876543).

The spelling of 21343442231 in words is "twenty-one billion, three hundred forty-three million, four hundred forty-two thousand, two hundred thirty-one".