21431121121423 has 8 divisors (see below), whose sum is σ = 23115340731168. Its totient is φ = 19751997487584.

The previous prime is 21431121121411. The next prime is 21431121121441. The reversal of 21431121121423 is 32412112113412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21431121121423 is a prime.

It is a super-2 number, since 2×21431121121423² (a number of 27 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 = 21431121121391 and 21431121121400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431121122423) 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, 1273985236 + ... + 1274002057.

It is an arithmetic number, because the mean of its divisors is an integer number (2889417591396).

Almost surely, 2^{21431121121423} is an apocalyptic number.

21431121121423 is a deficient number, since it is larger than the sum of its proper divisors (1684219609745).

21431121121423 is a wasteful number, since it uses less digits than its factorization.

21431121121423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2547987953.

The product of its digits is 2304, while the sum is 28.

Adding to 21431121121423 its reverse (32412112113412), we get a palindrome (53843233234835).

The spelling of 21431121121423 in words is "twenty-one trillion, four hundred thirty-one billion, one hundred twenty-one million, one hundred twenty-one thousand, four hundred twenty-three".