27681641 has 4 divisors (see below), whose sum is σ = 29811012. Its totient is φ = 25552272.

The previous prime is 27681571. The next prime is 27681671. The reversal of 27681641 is 14618672.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18705625 + 8976016 = 4325^2 + 2996^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27681641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27681671) 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 in 3 ways as a sum of consecutive naturals, for example, 1064666 + ... + 1064691.

It is an arithmetic number, because the mean of its divisors is an integer number (7452753).

Almost surely, 2^27681641 is an apocalyptic number.

It is an amenable number.

27681641 is a deficient number, since it is larger than the sum of its proper divisors (2129371).

27681641 is a wasteful number, since it uses less digits than its factorization.

27681641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2129370.

The product of its digits is 16128, while the sum is 35.

The square root of 27681641 is about 5261.3345265246. The cubic root of 27681641 is about 302.5036440606.

The spelling of 27681641 in words is "twenty-seven million, six hundred eighty-one thousand, six hundred forty-one".