21431241340423 has 4 divisors (see below), whose sum is σ = 22691902595760. Its totient is φ = 20170580085088.

The previous prime is 21431241340381. The next prime is 21431241340463. The reversal of 21431241340423 is 32404314213412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21431241340423 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 (21431241340463) 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, 630330627643 + ... + 630330627676.

It is an arithmetic number, because the mean of its divisors is an integer number (5672975648940).

Almost surely, 2^{21431241340423} is an apocalyptic number.

21431241340423 is a deficient number, since it is larger than the sum of its proper divisors (1260661255337).

21431241340423 is a wasteful number, since it uses less digits than its factorization.

21431241340423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260661255336.

The product of its (nonzero) digits is 55296, while the sum is 34.

Adding to 21431241340423 its reverse (32404314213412), we get a palindrome (53835555553835).

The spelling of 21431241340423 in words is "twenty-one trillion, four hundred thirty-one billion, two hundred forty-one million, three hundred forty thousand, four hundred twenty-three".