6531121243 has 2 divisors, whose sum is σ = 6531121244. Its totient is φ = 6531121242.

The previous prime is 6531121241. The next prime is 6531121271. The reversal of 6531121243 is 3421211356.

It is an a-pointer prime, because the next prime (6531121271) can be obtained adding 6531121243 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6531121243 - 2¹ = 6531121241 is a prime.

Together with 6531121241, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6531121241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3265560621 + 3265560622.

It is an arithmetic number, because the mean of its divisors is an integer number (3265560622).

Almost surely, 2^6531121243 is an apocalyptic number.

6531121243 is a deficient number, since it is larger than the sum of its proper divisors (1).

6531121243 is an equidigital number, since it uses as much as digits as its factorization.

6531121243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The square root of 6531121243 is about 80815.3527678992. The cubic root of 6531121243 is about 1869.2293089418.

Adding to 6531121243 its reverse (3421211356), we get a palindrome (9952332599).

The spelling of 6531121243 in words is "six billion, five hundred thirty-one million, one hundred twenty-one thousand, two hundred forty-three".