12227978921 has 2 divisors, whose sum is σ = 12227978922. Its totient is φ = 12227978920.

The previous prime is 12227978887. The next prime is 12227978989. The reversal of 12227978921 is 12987972221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10032025600 + 2195953321 = 100160^2 + 46861^2 .

It is a cyclic number.

It is not a de Polignac number, because 12227978921 - 2⁶ = 12227978857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12227978921.

It is not a weakly prime, because it can be changed into another prime (12227974921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6113989460 + 6113989461.

It is an arithmetic number, because the mean of its divisors is an integer number (6113989461).

Almost surely, 2^12227978921 is an apocalyptic number.

It is an amenable number.

12227978921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12227978921 is an equidigital number, since it uses as much as digits as its factorization.

12227978921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 50.

The spelling of 12227978921 in words is "twelve billion, two hundred twenty-seven million, nine hundred seventy-eight thousand, nine hundred twenty-one".