1286643295809 has 9 divisors (see below), whose sum is σ = 1858489675939. Its totient is φ = 857759928600.

The previous prime is 1286643295807. The next prime is 1286643295901. The reversal of 1286643295809 is 9085923466821.

The square root of 1286643295809 is 1134303.

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

1286643295809 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 6 + 43 + 2 + 9 + 580 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1066888607409 + 219754688400 = 1032903^2 + 468780^2 .

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

It is not a de Polignac number, because 1286643295809 - 2¹ = 1286643295807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1286643295807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3213859 + ... + 3591959.

Almost surely, 2^{1286643295809} is an apocalyptic number.

1286643295809 is the 1134303-rd square number.

1286643295809 is the 567152-nd centered octagonal number.

It is an amenable number.

1286643295809 is a deficient number, since it is larger than the sum of its proper divisors (571846380130).

1286643295809 is an frugal number, since it uses more digits than its factorization.

1286643295809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756208 (or 378104 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 63.

The spelling of 1286643295809 in words is "one trillion, two hundred eighty-six billion, six hundred forty-three million, two hundred ninety-five thousand, eight hundred nine".