9001020209 has 4 divisors (see below), whose sum is σ = 9530492004. Its totient is φ = 8471548416.

The previous prime is 9001020179. The next prime is 9001020211. The reversal of 9001020209 is 9020201009.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5008675984 + 3992344225 = 70772^2 + 63185^2 .

It is a cyclic number.

It is not a de Polignac number, because 9001020209 - 2⁸ = 9001019953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9001020289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264735872 + ... + 264735905.

It is an arithmetic number, because the mean of its divisors is an integer number (2382623001).

Almost surely, 2^9001020209 is an apocalyptic number.

It is an amenable number.

9001020209 is a deficient number, since it is larger than the sum of its proper divisors (529471795).

9001020209 is a wasteful number, since it uses less digits than its factorization.

9001020209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529471794.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 9001020209 is about 94873.7066262302. The cubic root of 9001020209 is about 2080.1624171281.

The spelling of 9001020209 in words is "nine billion, one million, twenty thousand, two hundred nine".