6540662209 has 2 divisors, whose sum is σ = 6540662210. Its totient is φ = 6540662208.

The previous prime is 6540662173. The next prime is 6540662251. The reversal of 6540662209 is 9022660456.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6503938609 + 36723600 = 80647^2 + 6060^2 .

It is a cyclic number.

It is not a de Polignac number, because 6540662209 - 2¹³ = 6540654017 is a prime.

It is not a weakly prime, because it can be changed into another prime (6540612209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3270331104 + 3270331105.

It is an arithmetic number, because the mean of its divisors is an integer number (3270331105).

Almost surely, 2^6540662209 is an apocalyptic number.

It is an amenable number.

6540662209 is a deficient number, since it is larger than the sum of its proper divisors (1).

6540662209 is an equidigital number, since it uses as much as digits as its factorization.

6540662209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 6540662209 is about 80874.3606404403. The cubic root of 6540662209 is about 1870.1390851396.

The spelling of 6540662209 in words is "six billion, five hundred forty million, six hundred sixty-two thousand, two hundred nine".