21431340343 has 12 divisors (see below), whose sum is σ = 26018475952. Its totient is φ = 17289146880.

The previous prime is 21431340313. The next prime is 21431340349. The reversal of 21431340343 is 34304313412.

It is not a de Polignac number, because 21431340343 - 2⁵ = 21431340311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431340349) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5294898 + ... + 5298943.

Almost surely, 2^21431340343 is an apocalyptic number.

21431340343 is a deficient number, since it is larger than the sum of its proper divisors (4587135609).

21431340343 is a wasteful number, since it uses less digits than its factorization.

21431340343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10593882 (or 10593865 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 28.

Adding to 21431340343 its reverse (34304313412), we get a palindrome (55735653755).

The spelling of 21431340343 in words is "twenty-one billion, four hundred thirty-one million, three hundred forty thousand, three hundred forty-three".