27978943 has 2 divisors, whose sum is σ = 27978944. Its totient is φ = 27978942.

The previous prime is 27978871. The next prime is 27978967. The reversal of 27978943 is 34987972.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27978943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27978983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13989471 + 13989472.

It is an arithmetic number, because the mean of its divisors is an integer number (13989472).

Almost surely, 2^27978943 is an apocalyptic number.

27978943 is a deficient number, since it is larger than the sum of its proper divisors (1).

27978943 is an equidigital number, since it uses as much as digits as its factorization.

27978943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 49.

The square root of 27978943 is about 5289.5125484301. The cubic root of 27978943 is about 303.5827573192.

The spelling of 27978943 in words is "twenty-seven million, nine hundred seventy-eight thousand, nine hundred forty-three".