12020078721 has 12 divisors (see below), whose sum is σ = 18643387632. Its totient is φ = 6868616328.

The previous prime is 12020078711. The next prime is 12020078747. The reversal of 12020078721 is 12787002021.

It is a happy number.

It is not a de Polignac number, because 12020078721 - 2⁹ = 12020078209 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12020078711) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40884475 + ... + 40884768.

It is an arithmetic number, because the mean of its divisors is an integer number (1553615636).

Almost surely, 2^12020078721 is an apocalyptic number.

It is an amenable number.

12020078721 is a deficient number, since it is larger than the sum of its proper divisors (6623308911).

12020078721 is an equidigital number, since it uses as much as digits as its factorization.

12020078721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81769260 (or 81769253 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The spelling of 12020078721 in words is "twelve billion, twenty million, seventy-eight thousand, seven hundred twenty-one".