27681521 has 12 divisors (see below), whose sum is σ = 32613120. Its totient is φ = 23423400.

The previous prime is 27681469. The next prime is 27681523. The reversal of 27681521 is 12518672.

It is a de Polignac number, because none of the positive numbers 2^k-27681521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (27681523) 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 11 ways as a sum of consecutive naturals, for example, 296 + ... + 7446.

It is an arithmetic number, because the mean of its divisors is an integer number (2717760).

Almost surely, 2^27681521 is an apocalyptic number.

It is an amenable number.

27681521 is a deficient number, since it is larger than the sum of its proper divisors (4931599).

27681521 is an equidigital number, since it uses as much as digits as its factorization.

27681521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7244 (or 7237 counting only the distinct ones).

The product of its digits is 6720, while the sum is 32.

The square root of 27681521 is about 5261.3231225615. The cubic root of 27681521 is about 302.5032069418.

The spelling of 27681521 in words is "twenty-seven million, six hundred eighty-one thousand, five hundred twenty-one".