27861881 has 4 divisors (see below), whose sum is σ = 27931764. Its totient is φ = 27792000.

The previous prime is 27861877. The next prime is 27861931. The reversal of 27861881 is 18816872.

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 22005481 + 5856400 = 4691^2 + 2420^2 .

It is a cyclic number.

It is not a de Polignac number, because 27861881 - 2² = 27861877 is a prime.

It is a super-2 number, since 2×27861881² = 1552568825716322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27801881) 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, 34340 + ... + 35141.

It is an arithmetic number, because the mean of its divisors is an integer number (6982941).

Almost surely, 2^27861881 is an apocalyptic number.

It is an amenable number.

27861881 is a deficient number, since it is larger than the sum of its proper divisors (69883).

27861881 is an equidigital number, since it uses as much as digits as its factorization.

27861881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69882.

The product of its digits is 43008, while the sum is 41.

The square root of 27861881 is about 5278.4354689624. The cubic root of 27861881 is about 303.1587755754.

The spelling of 27861881 in words is "twenty-seven million, eight hundred sixty-one thousand, eight hundred eighty-one".