202009 has 4 divisors (see below), whose sum is σ = 210816. Its totient is φ = 193204.

The previous prime is 202001. The next prime is 202021. The reversal of 202009 is 900202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 900202 = 2 ⋅450101.

It is a cyclic number.

It is not a de Polignac number, because 202009 - 2³ = 202001 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 202009.

It is not an unprimeable number, because it can be changed into a prime (202001) 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, 4369 + ... + 4414.

It is an arithmetic number, because the mean of its divisors is an integer number (52704).

2²⁰²⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

202009 is a deficient number, since it is larger than the sum of its proper divisors (8807).

202009 is an equidigital number, since it uses as much as digits as its factorization.

202009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8806.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 202009 is about 449.4541133420. The cubic root of 202009 is about 58.6755144771.

The spelling of 202009 in words is "two hundred two thousand, nine".