27689881 has 2 divisors, whose sum is σ = 27689882. Its totient is φ = 27689880.

The previous prime is 27689869. The next prime is 27689887. The reversal of 27689881 is 18898672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17347225 + 10342656 = 4165^2 + 3216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27689881 is a prime.

It is a super-2 number, since 2×27689881² = 1533459019588322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27689887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13844940 + 13844941.

It is an arithmetic number, because the mean of its divisors is an integer number (13844941).

Almost surely, 2^27689881 is an apocalyptic number.

It is an amenable number.

27689881 is a deficient number, since it is larger than the sum of its proper divisors (1).

27689881 is an equidigital number, since it uses as much as digits as its factorization.

27689881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 49.

The square root of 27689881 is about 5262.1175395462. The cubic root of 27689881 is about 302.5336565243.

The spelling of 27689881 in words is "twenty-seven million, six hundred eighty-nine thousand, eight hundred eighty-one".