27813661 has 4 divisors (see below), whose sum is σ = 27912924. Its totient is φ = 27714400.

The previous prime is 27813641. The next prime is 27813671. The reversal of 27813661 is 16631872.

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 9272025 + 18541636 = 3045^2 + 4306^2 .

It is a cyclic number.

It is not a de Polignac number, because 27813661 - 2¹⁹ = 27289373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27813641) 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, 49210 + ... + 49771.

It is an arithmetic number, because the mean of its divisors is an integer number (6978231).

Almost surely, 2^27813661 is an apocalyptic number.

It is an amenable number.

27813661 is a deficient number, since it is larger than the sum of its proper divisors (99263).

27813661 is an equidigital number, since it uses as much as digits as its factorization.

27813661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99262.

The product of its digits is 12096, while the sum is 34.

The square root of 27813661 is about 5273.8658496401. The cubic root of 27813661 is about 302.9837843094.

The spelling of 27813661 in words is "twenty-seven million, eight hundred thirteen thousand, six hundred sixty-one".