12649541809 has 2 divisors, whose sum is σ = 12649541810. Its totient is φ = 12649541808.

The previous prime is 12649541791. The next prime is 12649541843. The reversal of 12649541809 is 90814594621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11353541809 + 1296000000 = 106553^2 + 36000^2 .

It is a cyclic number.

It is not a de Polignac number, because 12649541809 - 2²⁹ = 12112670897 is a prime.

It is not a weakly prime, because it can be changed into another prime (12649541209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6324770904 + 6324770905.

It is an arithmetic number, because the mean of its divisors is an integer number (6324770905).

Almost surely, 2^12649541809 is an apocalyptic number.

It is an amenable number.

12649541809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12649541809 is an equidigital number, since it uses as much as digits as its factorization.

12649541809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 49.

The spelling of 12649541809 in words is "twelve billion, six hundred forty-nine million, five hundred forty-one thousand, eight hundred nine".