6540203631609 has 6 divisors (see below), whose sum is σ = 9446960801226. Its totient is φ = 4360135754400.

The previous prime is 6540203631589. The next prime is 6540203631623. The reversal of 6540203631609 is 9061363020456.

6540203631609 is a `hidden beast` number, since 6 + 5 + 4 + 0 + 2 + 0 + 3 + 6 + 31 + 609 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6485314170384 + 54889461225 = 2546628^2 + 234285^2 .

It is not a de Polignac number, because 6540203631609 - 2²⁷ = 6540069413881 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6540203631629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 363344646192 + ... + 363344646209.

It is an arithmetic number, because the mean of its divisors is an integer number (1574493466871).

Almost surely, 2^{6540203631609} is an apocalyptic number.

It is an amenable number.

6540203631609 is a deficient number, since it is larger than the sum of its proper divisors (2906757169617).

6540203631609 is a wasteful number, since it uses less digits than its factorization.

6540203631609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726689292407 (or 726689292404 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 45.

The spelling of 6540203631609 in words is "six trillion, five hundred forty billion, two hundred three million, six hundred thirty-one thousand, six hundred nine".