27726661381 has 2 divisors, whose sum is σ = 27726661382. Its totient is φ = 27726661380.

The previous prime is 27726661357. The next prime is 27726661393. The reversal of 27726661381 is 18316662772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27683968225 + 42693156 = 166385^2 + 6534^2 .

It is a cyclic number.

It is not a de Polignac number, because 27726661381 - 2¹³ = 27726653189 is a prime.

It is a super-2 number, since 2×27726661381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27726661331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13863330690 + 13863330691.

It is an arithmetic number, because the mean of its divisors is an integer number (13863330691).

Almost surely, 2^27726661381 is an apocalyptic number.

It is an amenable number.

27726661381 is a deficient number, since it is larger than the sum of its proper divisors (1).

27726661381 is an equidigital number, since it uses as much as digits as its factorization.

27726661381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 49.

The spelling of 27726661381 in words is "twenty-seven billion, seven hundred twenty-six million, six hundred sixty-one thousand, three hundred eighty-one".