27331781 has 2 divisors, whose sum is σ = 27331782. Its totient is φ = 27331780.

The previous prime is 27331763. The next prime is 27331783. The reversal of 27331781 is 18713372.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18576100 + 8755681 = 4310^2 + 2959^2 .

It is a cyclic number.

It is not a de Polignac number, because 27331781 - 2¹⁴ = 27315397 is a prime.

It is a super-2 number, since 2×27331781² = 1494052505263922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 27331783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27331783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13665890 + 13665891.

It is an arithmetic number, because the mean of its divisors is an integer number (13665891).

Almost surely, 2^27331781 is an apocalyptic number.

It is an amenable number.

27331781 is a deficient number, since it is larger than the sum of its proper divisors (1).

27331781 is an equidigital number, since it uses as much as digits as its factorization.

27331781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 32.

The square root of 27331781 is about 5227.9805852738. The cubic root of 27331781 is about 301.2238192843.

The spelling of 27331781 in words is "twenty-seven million, three hundred thirty-one thousand, seven hundred eighty-one".