20121312121 has 8 divisors (see below), whose sum is σ = 20827672200. Its totient is φ = 19415786880.

The previous prime is 20121312089. The next prime is 20121312137. The reversal of 20121312121 is 12121312102.

It can be written as a sum of positive squares in 4 ways, for example, as 103306896 + 20018005225 = 10164^2 + 141485^2 .

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 20121312121 - 2⁵ = 20121312089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121312095 and 20121312104.

It is not an unprimeable number, because it can be changed into a prime (20121312191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159460 + ... + 256261.

It is an arithmetic number, because the mean of its divisors is an integer number (2603459025).

Almost surely, 2^20121312121 is an apocalyptic number.

It is an amenable number.

20121312121 is a deficient number, since it is larger than the sum of its proper divisors (706360079).

20121312121 is a wasteful number, since it uses less digits than its factorization.

20121312121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417419.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20121312121 its reverse (12121312102), we get a palindrome (32242624223).

The spelling of 20121312121 in words is "twenty billion, one hundred twenty-one million, three hundred twelve thousand, one hundred twenty-one".