27797981 has 2 divisors, whose sum is σ = 27797982. Its totient is φ = 27797980.

The previous prime is 27797977. The next prime is 27798011. The reversal of 27797981 is 18979772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27394756 + 403225 = 5234^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 27797981 - 2² = 27797977 is a prime.

It is a super-2 number, since 2×27797981² = 1545455495352722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27797971) 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, 13898990 + 13898991.

It is an arithmetic number, because the mean of its divisors is an integer number (13898991).

Almost surely, 2^27797981 is an apocalyptic number.

It is an amenable number.

27797981 is a deficient number, since it is larger than the sum of its proper divisors (1).

27797981 is an equidigital number, since it uses as much as digits as its factorization.

27797981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 444528, while the sum is 50.

The square root of 27797981 is about 5272.3790645211. The cubic root of 27797981 is about 302.9268377275.

The spelling of 27797981 in words is "twenty-seven million, seven hundred ninety-seven thousand, nine hundred eighty-one".