6531391 has 2 divisors, whose sum is σ = 6531392. Its totient is φ = 6531390.

The previous prime is 6531377. The next prime is 6531401. The reversal of 6531391 is 1931356.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6531391 - 2⁹ = 6530879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6531191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3265695 + 3265696.

It is an arithmetic number, because the mean of its divisors is an integer number (3265696).

Almost surely, 2^6531391 is an apocalyptic number.

6531391 is a deficient number, since it is larger than the sum of its proper divisors (1).

6531391 is an equidigital number, since it uses as much as digits as its factorization.

6531391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2430, while the sum is 28.

The square root of 6531391 is about 2555.6586235255. The cubic root of 6531391 is about 186.9255043714.

The spelling of 6531391 in words is "six million, five hundred thirty-one thousand, three hundred ninety-one".