6540370891 has 2 divisors, whose sum is σ = 6540370892. Its totient is φ = 6540370890.

The previous prime is 6540370861. The next prime is 6540370933. The reversal of 6540370891 is 1980730456.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6540370891 - 2⁷ = 6540370763 is a prime.

It is not a weakly prime, because it can be changed into another prime (6540370861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3270185445 + 3270185446.

It is an arithmetic number, because the mean of its divisors is an integer number (3270185446).

Almost surely, 2^6540370891 is an apocalyptic number.

6540370891 is a deficient number, since it is larger than the sum of its proper divisors (1).

6540370891 is an equidigital number, since it uses as much as digits as its factorization.

6540370891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 6540370891 is about 80872.5595675072. The cubic root of 6540370891 is about 1870.1113196907. Note that the first 3 decimals are identical.

The spelling of 6540370891 in words is "six billion, five hundred forty million, three hundred seventy thousand, eight hundred ninety-one".