27771001 has 2 divisors, whose sum is σ = 27771002. Its totient is φ = 27771000.

The previous prime is 27770999. The next prime is 27771017. The reversal of 27771001 is 10017772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27092025 + 678976 = 5205^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 27771001 - 2¹ = 27770999 is a prime.

Together with 27770999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (27771091) 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, 13885500 + 13885501.

It is an arithmetic number, because the mean of its divisors is an integer number (13885501).

Almost surely, 2^27771001 is an apocalyptic number.

It is an amenable number.

27771001 is a deficient number, since it is larger than the sum of its proper divisors (1).

27771001 is an equidigital number, since it uses as much as digits as its factorization.

27771001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 686, while the sum is 25.

The square root of 27771001 is about 5269.8198261421. The cubic root of 27771001 is about 302.8288016907.

Adding to 27771001 its reverse (10017772), we get a palindrome (37788773).

The spelling of 27771001 in words is "twenty-seven million, seven hundred seventy-one thousand, one".