12121891603 has 4 divisors (see below), whose sum is σ = 12125672280. Its totient is φ = 12118110928.

The previous prime is 12121891597. The next prime is 12121891619. The reversal of 12121891603 is 30619812121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30619812121 = 19 ⋅1611569059.

It is a cyclic number.

It is not a de Polignac number, because 12121891603 - 2⁵ = 12121891571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12121891673) 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, 1885525 + ... + 1891942.

It is an arithmetic number, because the mean of its divisors is an integer number (3031418070).

Almost surely, 2^12121891603 is an apocalyptic number.

12121891603 is a deficient number, since it is larger than the sum of its proper divisors (3780677).

12121891603 is an equidigital number, since it uses as much as digits as its factorization.

12121891603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780676.

The product of its (nonzero) digits is 5184, while the sum is 34.

The spelling of 12121891603 in words is "twelve billion, one hundred twenty-one million, eight hundred ninety-one thousand, six hundred three".