12121011209 has 4 divisors (see below), whose sum is σ = 12135155604. Its totient is φ = 12106866816.

The previous prime is 12121011173. The next prime is 12121011223. The reversal of 12121011209 is 90211012121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90211012121 = 3343 ⋅26985047.

It can be written as a sum of positive squares in 2 ways, for example, as 11782451209 + 338560000 = 108547^2 + 18400^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121011209 - 2¹² = 12121007113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12121011229) 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, 7070912 + ... + 7072625.

It is an arithmetic number, because the mean of its divisors is an integer number (3033788901).

Almost surely, 2^12121011209 is an apocalyptic number.

It is an amenable number.

12121011209 is a deficient number, since it is larger than the sum of its proper divisors (14144395).

12121011209 is an equidigital number, since it uses as much as digits as its factorization.

12121011209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14144394.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 12121011209 in words is "twelve billion, one hundred twenty-one million, eleven thousand, two hundred nine".