12799999981 has 2 divisors, whose sum is σ = 12799999982. Its totient is φ = 12799999980.

The previous prime is 12799999957. The next prime is 12800000021. The reversal of 12799999981 is 18999999721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10173949956 + 2626050025 = 100866^2 + 51245^2 .

It is a cyclic number.

It is not a de Polignac number, because 12799999981 - 2³¹ = 10652516333 is a prime.

It is a super-2 number, since 2×12799999981² (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 (12799999921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6399999990 + 6399999991.

It is an arithmetic number, because the mean of its divisors is an integer number (6399999991).

Almost surely, 2^12799999981 is an apocalyptic number.

It is an amenable number.

12799999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12799999981 is an equidigital number, since it uses as much as digits as its factorization.

12799999981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59521392, while the sum is 73.

The spelling of 12799999981 in words is "twelve billion, seven hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".