27661005 has 24 divisors (see below), whose sum is σ = 48447672. Its totient is φ = 14598144.

The previous prime is 27661003. The next prime is 27661013. The reversal of 27661005 is 50016672.

It can be written as a sum of positive squares in 4 ways, for example, as 1313316 + 26347689 = 1146^2 + 5133^2 .

It is not a de Polignac number, because 27661005 - 2¹ = 27661003 is a prime.

It is a super-2 number, since 2×27661005² = 1530262395220050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 27661005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27661003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1197 + ... + 7533.

It is an arithmetic number, because the mean of its divisors is an integer number (2018653).

Almost surely, 2^27661005 is an apocalyptic number.

It is an amenable number.

27661005 is a deficient number, since it is larger than the sum of its proper divisors (20786667).

27661005 is a wasteful number, since it uses less digits than its factorization.

27661005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6445 (or 6442 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 27661005 is about 5259.3730614970. The cubic root of 27661005 is about 302.4284556346.

Adding to 27661005 its reverse (50016672), we get a palindrome (77677677).

The spelling of 27661005 in words is "twenty-seven million, six hundred sixty-one thousand, five".