12466991981 has 2 divisors, whose sum is σ = 12466991982. Its totient is φ = 12466991980.

The previous prime is 12466991959. The next prime is 12466991989. The reversal of 12466991981 is 18919966421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11293312900 + 1173679081 = 106270^2 + 34259^2 .

It is a cyclic number.

It is not a de Polignac number, because 12466991981 - 2¹⁰ = 12466990957 is a prime.

It is a super-2 number, since 2×12466991981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12466991989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6233495990 + 6233495991.

It is an arithmetic number, because the mean of its divisors is an integer number (6233495991).

Almost surely, 2^12466991981 is an apocalyptic number.

It is an amenable number.

12466991981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12466991981 is an equidigital number, since it uses as much as digits as its factorization.

12466991981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1679616, while the sum is 56.

The spelling of 12466991981 in words is "twelve billion, four hundred sixty-six million, nine hundred ninety-one thousand, nine hundred eighty-one".