12001243981 has 2 divisors, whose sum is σ = 12001243982. Its totient is φ = 12001243980.

The previous prime is 12001243979. The next prime is 12001243997. The reversal of 12001243981 is 18934210021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11720011081 + 281232900 = 108259^2 + 16770^2 .

It is a cyclic number.

It is not a de Polignac number, because 12001243981 - 2¹ = 12001243979 is a prime.

It is a super-2 number, since 2×12001243981² (a number of 21 digits) contains 22 as substring.

Together with 12001243979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12001243901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6000621990 + 6000621991.

It is an arithmetic number, because the mean of its divisors is an integer number (6000621991).

Almost surely, 2^12001243981 is an apocalyptic number.

It is an amenable number.

12001243981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12001243981 is an equidigital number, since it uses as much as digits as its factorization.

12001243981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 31.

The spelling of 12001243981 in words is "twelve billion, one million, two hundred forty-three thousand, nine hundred eighty-one".