20121441209 has 4 divisors (see below), whose sum is σ = 20137552500. Its totient is φ = 20105329920.

The previous prime is 20121441169. The next prime is 20121441253. The reversal of 20121441209 is 90214412102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90214412102 = 2 ⋅45107206051.

It can be written as a sum of positive squares in 2 ways, for example, as 12143378809 + 7978062400 = 110197^2 + 89320^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121441209 - 2²⁴ = 20104663993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121441289) 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, 8053772 + ... + 8056269.

It is an arithmetic number, because the mean of its divisors is an integer number (5034388125).

Almost surely, 2^20121441209 is an apocalyptic number.

It is an amenable number.

20121441209 is a deficient number, since it is larger than the sum of its proper divisors (16111291).

20121441209 is a wasteful number, since it uses less digits than its factorization.

20121441209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16111290.

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 20121441209 in words is "twenty billion, one hundred twenty-one million, four hundred forty-one thousand, two hundred nine".