654131209 has 2 divisors, whose sum is σ = 654131210. Its totient is φ = 654131208.

The previous prime is 654131207. The next prime is 654131249. The reversal of 654131209 is 902131456.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 339849225 + 314281984 = 18435^2 + 17728^2 .

It is a cyclic number.

It is not a de Polignac number, because 654131209 - 2¹ = 654131207 is a prime.

Together with 654131207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (654131207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327065604 + 327065605.

It is an arithmetic number, because the mean of its divisors is an integer number (327065605).

Almost surely, 2^654131209 is an apocalyptic number.

It is an amenable number.

654131209 is a deficient number, since it is larger than the sum of its proper divisors (1).

654131209 is an equidigital number, since it uses as much as digits as its factorization.

654131209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 654131209 is about 25575.9889153870. The cubic root of 654131209 is about 868.0704181121.

The spelling of 654131209 in words is "six hundred fifty-four million, one hundred thirty-one thousand, two hundred nine".