12291005257609 has 27 divisors (see below), whose sum is σ = 13534016648607. Its totient is φ = 11157026587200.

The previous prime is 12291005257591. The next prime is 12291005257747. The reversal of 12291005257609 is 90675250019221.

The square root of 12291005257609 is 3505853.

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

It can be written as a sum of positive squares in 13 ways, for example, as 12009863525625 + 281141731984 = 3465525^2 + 530228^2 .

It is not a de Polignac number, because 12291005257609 - 2⁷ = 12291005257481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12291005257009) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2780139219 + ... + 2780143639.

Almost surely, 2^{12291005257609} is an apocalyptic number.

12291005257609 is the 3505853-rd square number.

12291005257609 is the 1752927-th centered octagonal number.

It is an amenable number.

12291005257609 is a deficient number, since it is larger than the sum of its proper divisors (1243011390998).

12291005257609 is an frugal number, since it uses more digits than its factorization.

12291005257609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8990 (or 4495 counting only the distinct ones).

The product of its (nonzero) digits is 680400, while the sum is 49.

Multiplying 12291005257609 by its sum of digits (49), we get a square (602259257622841 = 24540971²).

The spelling of 12291005257609 in words is "twelve trillion, two hundred ninety-one billion, five million, two hundred fifty-seven thousand, six hundred nine".