21343443131 has 2 divisors, whose sum is σ = 21343443132. Its totient is φ = 21343443130.

The previous prime is 21343443097. The next prime is 21343443137. The reversal of 21343443131 is 13134434312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21343443131 is a prime.

It is a super-2 number, since 2×21343443131² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21343443094 and 21343443103.

It is not a weakly prime, because it can be changed into another prime (21343443137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671721565 + 10671721566.

It is an arithmetic number, because the mean of its divisors is an integer number (10671721566).

Almost surely, 2^21343443131 is an apocalyptic number.

21343443131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21343443131 is an equidigital number, since it uses as much as digits as its factorization.

21343443131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 29.

Adding to 21343443131 its reverse (13134434312), we get a palindrome (34477877443).

The spelling of 21343443131 in words is "twenty-one billion, three hundred forty-three million, four hundred forty-three thousand, one hundred thirty-one".