12121807720 has 64 divisors (see below), whose sum is σ = 31319524800. Its totient is φ = 4175930880.

The previous prime is 12121807703. The next prime is 12121807723. The reversal of 12121807720 is 2770812121.

It is not an unprimeable number, because it can be changed into a prime (12121807723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 716629 + ... + 733348.

It is an arithmetic number, because the mean of its divisors is an integer number (489367575).

Almost surely, 2^12121807720 is an apocalyptic number.

12121807720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121807720 is an abundant number, since it is smaller than the sum of its proper divisors (19197717080).

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

12121807720 is a wasteful number, since it uses less digits than its factorization.

12121807720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450018 (or 1450014 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 31.

The spelling of 12121807720 in words is "twelve billion, one hundred twenty-one million, eight hundred seven thousand, seven hundred twenty".