20231209 has 8 divisors (see below), whose sum is σ = 20524032. Its totient is φ = 19940400.

The previous prime is 20231203. The next prime is 20231243. The reversal of 20231209 is 90213202.

It is a happy number.

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 20231209 - 2¹¹ = 20229161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20231203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38422 + ... + 38944.

It is an arithmetic number, because the mean of its divisors is an integer number (2565504).

Almost surely, 2^20231209 is an apocalyptic number.

It is an amenable number.

20231209 is a deficient number, since it is larger than the sum of its proper divisors (292823).

20231209 is a wasteful number, since it uses less digits than its factorization.

20231209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 20231209 is about 4497.9116265218. The cubic root of 20231209 is about 272.4837529241.

The spelling of 20231209 in words is "twenty million, two hundred thirty-one thousand, two hundred nine".