27019981 has 2 divisors, whose sum is σ = 27019982. Its totient is φ = 27019980.

The previous prime is 27019907. The next prime is 27020023. The reversal of 27019981 is 18991072.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21473956 + 5546025 = 4634^2 + 2355^2 .

It is a cyclic number.

It is not a de Polignac number, because 27019981 - 2¹¹ = 27017933 is a prime.

It is a super-2 number, since 2×27019981² = 1460158746480722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 27019981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27019381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13509990 + 13509991.

It is an arithmetic number, because the mean of its divisors is an integer number (13509991).

Almost surely, 2^27019981 is an apocalyptic number.

It is an amenable number.

27019981 is a deficient number, since it is larger than the sum of its proper divisors (1).

27019981 is an equidigital number, since it uses as much as digits as its factorization.

27019981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 27019981 is about 5198.0747397474. The cubic root of 27019981 is about 300.0739854560.

The spelling of 27019981 in words is "twenty-seven million, nineteen thousand, nine hundred eighty-one".