8501872145209 has 45 divisors (see below), whose sum is σ = 9245345640221. Its totient is φ = 7818068180160.

The previous prime is 8501872145201. The next prime is 8501872145219. The reversal of 8501872145209 is 9025412781058.

The square root of 8501872145209 is 2915797.

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 52548685225 + 8449323459984 = 229235^2 + 2906772^2 .

It is not a de Polignac number, because 8501872145209 - 2³ = 8501872145201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8501872145201) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 43156711299 + ... + 43156711495.

Almost surely, 2^{8501872145209} is an apocalyptic number.

8501872145209 is the 2915797-th square number.

8501872145209 is the 1457899-th centered octagonal number.

It is an amenable number.

8501872145209 is a deficient number, since it is larger than the sum of its proper divisors (743473495012).

8501872145209 is an frugal number, since it uses more digits than its factorization.

8501872145209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 52.

The spelling of 8501872145209 in words is "eight trillion, five hundred one billion, eight hundred seventy-two million, one hundred forty-five thousand, two hundred nine".