12981609 has 9 divisors (see below), whose sum is σ = 18766839. Its totient is φ = 8647200.

The previous prime is 12981601. The next prime is 12981611. The reversal of 12981609 is 90618921.

The square root of 12981609 is 3603.

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

12981609 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 21609 + 12960000 = 147^2 + 3600^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 12981609 - 2³ = 12981601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12981601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10209 + ... + 11409.

Almost surely, 2^12981609 is an apocalyptic number.

12981609 is the 3603-rd square number.

12981609 is the 1802-nd centered octagonal number.

It is an amenable number.

12981609 is a deficient number, since it is larger than the sum of its proper divisors (5785230).

12981609 is an frugal number, since it uses more digits than its factorization.

12981609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2408 (or 1204 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The cubic root of 12981609 is about 235.0225359405.

Multiplying 12981609 by its sum of digits (36), we get a square (467337924 = 21618²).

The spelling of 12981609 in words is "twelve million, nine hundred eighty-one thousand, six hundred nine".