2545505209 has 9 divisors (see below), whose sum is σ = 2757085869. Its totient is φ = 2349091680.

The previous prime is 2545505203. The next prime is 2545505273. The reversal of 2545505209 is 9025055452.

The square root of 2545505209 is 50453.

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 166797225 + 2378707984 = 12915^2 + 48772^2 .

It is not a de Polignac number, because 2545505209 - 2⁵ = 2545505177 is a prime.

It is a super-2 number, since 2×2545505209² = 12959193538092267362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2545505203) 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, 653949 + ... + 657829.

Almost surely, 2^2545505209 is an apocalyptic number.

2545505209 is the 50453-rd square number.

2545505209 is the 25227-th centered octagonal number.

It is an amenable number.

2545505209 is a deficient number, since it is larger than the sum of its proper divisors (211580660).

2545505209 is an frugal number, since it uses more digits than its factorization.

2545505209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7788 (or 3894 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 37.

The cubic root of 2545505209 is about 1365.3940207938.

Multiplying 2545505209 by its product of nonzero digits (90000), we get a square (229095468810000 = 15135900²).

The spelling of 2545505209 in words is "two billion, five hundred forty-five million, five hundred five thousand, two hundred nine".