27811961 has 2 divisors, whose sum is σ = 27811962. Its totient is φ = 27811960.

The previous prime is 27811939. The next prime is 27811969. The reversal of 27811961 is 16911872.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19971961 + 7840000 = 4469^2 + 2800^2 .

It is a cyclic number.

It is not a de Polignac number, because 27811961 - 2⁶ = 27811897 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27811969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13905980 + 13905981.

It is an arithmetic number, because the mean of its divisors is an integer number (13905981).

Almost surely, 2^27811961 is an apocalyptic number.

It is an amenable number.

27811961 is a deficient number, since it is larger than the sum of its proper divisors (1).

27811961 is an equidigital number, since it uses as much as digits as its factorization.

27811961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 35.

The square root of 27811961 is about 5273.7046750837. The cubic root of 27811961 is about 302.9776112885.

The spelling of 27811961 in words is "twenty-seven million, eight hundred eleven thousand, nine hundred sixty-one".