27918881 has 2 divisors, whose sum is σ = 27918882. Its totient is φ = 27918880.

The previous prime is 27918853. The next prime is 27918883. The reversal of 27918881 is 18881972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17774656 + 10144225 = 4216^2 + 3185^2 .

It is a cyclic number.

It is not a de Polignac number, because 27918881 - 2²² = 23724577 is a prime.

It is a super-2 number, since 2×27918881² = 1558927832584322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 27918883, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27918883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13959440 + 13959441.

It is an arithmetic number, because the mean of its divisors is an integer number (13959441).

Almost surely, 2^27918881 is an apocalyptic number.

It is an amenable number.

27918881 is a deficient number, since it is larger than the sum of its proper divisors (1).

27918881 is an equidigital number, since it uses as much as digits as its factorization.

27918881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 44.

The square root of 27918881 is about 5283.8320374516. The cubic root of 27918881 is about 303.3653694243.

The spelling of 27918881 in words is "twenty-seven million, nine hundred eighteen thousand, eight hundred eighty-one".