202121209 has 8 divisors (see below), whose sum is σ = 209544192. Its totient is φ = 194754720.

The previous prime is 202121203. The next prime is 202121219. The reversal of 202121209 is 902121202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 202121209 - 2⁷ = 202121081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (202121203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6769 + ... + 21214.

It is an arithmetic number, because the mean of its divisors is an integer number (26193024).

Almost surely, 2^202121209 is an apocalyptic number.

It is an amenable number.

202121209 is a deficient number, since it is larger than the sum of its proper divisors (7422983).

202121209 is a wasteful number, since it uses less digits than its factorization.

202121209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28247.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 202121209 is about 14216.9338818185. The cubic root of 202121209 is about 586.8637653790.

The spelling of 202121209 in words is "two hundred two million, one hundred twenty-one thousand, two hundred nine".