27755821 has 2 divisors, whose sum is σ = 27755822. Its totient is φ = 27755820.

The previous prime is 27755771. The next prime is 27755839. The reversal of 27755821 is 12855772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27185796 + 570025 = 5214^2 + 755^2 .

It is a cyclic number.

It is not a de Polignac number, because 27755821 - 2¹⁵ = 27723053 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 (27759821) 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, 13877910 + 13877911.

It is an arithmetic number, because the mean of its divisors is an integer number (13877911).

Almost surely, 2^27755821 is an apocalyptic number.

It is an amenable number.

27755821 is a deficient number, since it is larger than the sum of its proper divisors (1).

27755821 is an equidigital number, since it uses as much as digits as its factorization.

27755821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39200, while the sum is 37.

The square root of 27755821 is about 5268.3793523246. The cubic root of 27755821 is about 302.7736148785.

The spelling of 27755821 in words is "twenty-seven million, seven hundred fifty-five thousand, eight hundred twenty-one".