12001978789 has 2 divisors, whose sum is σ = 12001978790. Its totient is φ = 12001978788.

The previous prime is 12001978763. The next prime is 12001978823. The reversal of 12001978789 is 98787910021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7954856100 + 4047122689 = 89190^2 + 63617^2 .

It is a cyclic number.

It is not a de Polignac number, because 12001978789 - 2²⁹ = 11465107877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12001978739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6000989394 + 6000989395.

It is an arithmetic number, because the mean of its divisors is an integer number (6000989395).

Almost surely, 2^12001978789 is an apocalyptic number.

It is an amenable number.

12001978789 is a deficient number, since it is larger than the sum of its proper divisors (1).

12001978789 is an equidigital number, since it uses as much as digits as its factorization.

12001978789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 508032, while the sum is 52.

The spelling of 12001978789 in words is "twelve billion, one million, nine hundred seventy-eight thousand, seven hundred eighty-nine".