2009456507809 has 9 divisors (see below), whose sum is σ = 2022561123897. Its totient is φ = 1996436283504.

The previous prime is 2009456507767. The next prime is 2009456507837. The reversal of 2009456507809 is 9087056549002.

The square root of 2009456507809 is 1417553.

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

It can be written as a sum of positive squares in 4 ways, for example, as 513551390625 + 1495905117184 = 716625^2 + 1223072^2 .

It is not a de Polignac number, because 2009456507809 - 2²¹ = 2009454410657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2009456507809.

It is not an unprimeable number, because it can be changed into a prime (2009456507879) 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, 222551307 + ... + 222560335.

Almost surely, 2^{2009456507809} is an apocalyptic number.

2009456507809 is the 1417553-rd square number.

2009456507809 is the 708777-th centered octagonal number.

It is an amenable number.

2009456507809 is a deficient number, since it is larger than the sum of its proper divisors (13104616088).

2009456507809 is an frugal number, since it uses more digits than its factorization.

2009456507809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18372 (or 9186 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 55.

The spelling of 2009456507809 in words is "two trillion, nine billion, four hundred fifty-six million, five hundred seven thousand, eight hundred nine".