12905641609 has 9 divisors (see below), whose sum is σ = 15013610247. Its totient is φ = 11061296904.

The previous prime is 12905641607. The next prime is 12905641621. The reversal of 12905641609 is 90614650921.

The square root of 12905641609 is 113603.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 12589513209 + 316128400 = 112203^2 + 17780^2 .

It is not a de Polignac number, because 12905641609 - 2¹ = 12905641607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12905641607) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 787107 + ... + 803335.

Almost surely, 2^12905641609 is an apocalyptic number.

12905641609 is the 113603-rd square number.

12905641609 is the 56802-nd centered octagonal number.

It is an amenable number.

12905641609 is a deficient number, since it is larger than the sum of its proper divisors (2107968638).

12905641609 is an frugal number, since it uses more digits than its factorization.

12905641609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32472 (or 16236 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 43.

The spelling of 12905641609 in words is "twelve billion, nine hundred five million, six hundred forty-one thousand, six hundred nine".