27665861 has 2 divisors, whose sum is σ = 27665862. Its totient is φ = 27665860.

The previous prime is 27665837. The next prime is 27665887. The reversal of 27665861 is 16856672.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27363361 + 302500 = 5231^2 + 550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27665861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27665801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13832930 + 13832931.

It is an arithmetic number, because the mean of its divisors is an integer number (13832931).

Almost surely, 2^27665861 is an apocalyptic number.

It is an amenable number.

27665861 is a deficient number, since it is larger than the sum of its proper divisors (1).

27665861 is an equidigital number, since it uses as much as digits as its factorization.

27665861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 27665861 is about 5259.8346932199. The cubic root of 27665861 is about 302.4461521072.

The spelling of 27665861 in words is "twenty-seven million, six hundred sixty-five thousand, eight hundred sixty-one".