20121131320 has 64 divisors (see below), whose sum is σ = 49231255680. Its totient is φ = 7370274816.

The previous prime is 20121131293. The next prime is 20121131369. The reversal of 20121131320 is 2313112102.

It is a junction number, because it is equal to n+sod(n) for n = 20121131294 and 20121131303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 374704 + ... + 425023.

It is an arithmetic number, because the mean of its divisors is an integer number (769238370).

Almost surely, 2^20121131320 is an apocalyptic number.

20121131320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20121131320 is an abundant number, since it is smaller than the sum of its proper divisors (29110124360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20121131320 is a wasteful number, since it uses less digits than its factorization.

20121131320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799792 (or 799788 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 20121131320 its reverse (2313112102), we get a palindrome (22434243422).

The spelling of 20121131320 in words is "twenty billion, one hundred twenty-one million, one hundred thirty-one thousand, three hundred twenty".