27983861 has 2 divisors, whose sum is σ = 27983862. Its totient is φ = 27983860.

The previous prime is 27983833. The next prime is 27983863. The reversal of 27983861 is 16838972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20421361 + 7562500 = 4519^2 + 2750^2 .

It is a cyclic number.

It is not a de Polignac number, because 27983861 - 2⁶ = 27983797 is a prime.

Together with 27983863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27983863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13991930 + 13991931.

It is an arithmetic number, because the mean of its divisors is an integer number (13991931).

Almost surely, 2^27983861 is an apocalyptic number.

It is an amenable number.

27983861 is a deficient number, since it is larger than the sum of its proper divisors (1).

27983861 is an equidigital number, since it uses as much as digits as its factorization.

27983861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 27983861 is about 5289.9774101597. The cubic root of 27983861 is about 303.6005437015.

The spelling of 27983861 in words is "twenty-seven million, nine hundred eighty-three thousand, eight hundred sixty-one".