27881261 has 4 divisors (see below), whose sum is σ = 27961500. Its totient is φ = 27801024.

The previous prime is 27881257. The next prime is 27881263. The reversal of 27881261 is 16218872.

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 11519236 + 16362025 = 3394^2 + 4045^2 .

It is a cyclic number.

It is not a de Polignac number, because 27881261 - 2² = 27881257 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 (27881263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39596 + ... + 40293.

It is an arithmetic number, because the mean of its divisors is an integer number (6990375).

Almost surely, 2^27881261 is an apocalyptic number.

It is an amenable number.

27881261 is a deficient number, since it is larger than the sum of its proper divisors (80239).

27881261 is an equidigital number, since it uses as much as digits as its factorization.

27881261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80238.

The product of its digits is 10752, while the sum is 35.

The square root of 27881261 is about 5280.2709210797. The cubic root of 27881261 is about 303.2290490717.

The spelling of 27881261 in words is "twenty-seven million, eight hundred eighty-one thousand, two hundred sixty-one".