21423144131 has 4 divisors (see below), whose sum is σ = 21425682792. Its totient is φ = 21420605472.

The previous prime is 21423144109. The next prime is 21423144143. The reversal of 21423144131 is 13144132412.

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-21423144131 is a prime.

It is a super-2 number, since 2×21423144131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21423144131.

It is not an unprimeable number, because it can be changed into a prime (21423144191) 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, 1256630 + ... + 1273563.

It is an arithmetic number, because the mean of its divisors is an integer number (5356420698).

Almost surely, 2^21423144131 is an apocalyptic number.

21423144131 is a deficient number, since it is larger than the sum of its proper divisors (2538661).

21423144131 is an equidigital number, since it uses as much as digits as its factorization.

21423144131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2538660.

The product of its digits is 2304, while the sum is 26.

Adding to 21423144131 its reverse (13144132412), we get a palindrome (34567276543).

The spelling of 21423144131 in words is "twenty-one billion, four hundred twenty-three million, one hundred forty-four thousand, one hundred thirty-one".