20121219999 has 6 divisors (see below), whose sum is σ = 29063984456. Its totient is φ = 13414146660.

The previous prime is 20121219991. The next prime is 20121220027. The reversal of 20121219999 is 99991212102.

It is not a de Polignac number, because 20121219999 - 2³ = 20121219991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121219991) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1117845547 + ... + 1117845564.

Almost surely, 2^20121219999 is an apocalyptic number.

20121219999 is a deficient number, since it is larger than the sum of its proper divisors (8942764457).

20121219999 is a wasteful number, since it uses less digits than its factorization.

20121219999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2235691117 (or 2235691114 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The spelling of 20121219999 in words is "twenty billion, one hundred twenty-one million, two hundred nineteen thousand, nine hundred ninety-nine".