27726467981 has 2 divisors, whose sum is σ = 27726467982. Its totient is φ = 27726467980.

The previous prime is 27726467969. The next prime is 27726468013. The reversal of 27726467981 is 18976462772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23484030025 + 4242437956 = 153245^2 + 65134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27726467981 is a prime.

It is a super-2 number, since 2×27726467981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 27726467981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27726467911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13863233990 + 13863233991.

It is an arithmetic number, because the mean of its divisors is an integer number (13863233991).

Almost surely, 2^27726467981 is an apocalyptic number.

It is an amenable number.

27726467981 is a deficient number, since it is larger than the sum of its proper divisors (1).

27726467981 is an equidigital number, since it uses as much as digits as its factorization.

27726467981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14224896, while the sum is 59.

The spelling of 27726467981 in words is "twenty-seven billion, seven hundred twenty-six million, four hundred sixty-seven thousand, nine hundred eighty-one".