27128978 has 18 divisors (see below), whose sum is σ = 42479541. Its totient is φ = 12993624.

The previous prime is 27128953. The next prime is 27128987. The reversal of 27128978 is 87982172.

It can be written as a sum of positive squares in 2 ways, for example, as 27112849 + 16129 = 5207^2 + 127^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3683.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 213551 + ... + 213677.

Almost surely, 2^27128978 is an apocalyptic number.

27128978 is a deficient number, since it is larger than the sum of its proper divisors (15350563).

27128978 is an equidigital number, since it uses as much as digits as its factorization.

27128978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 158 counting only the distinct ones).

The product of its digits is 112896, while the sum is 44.

The square root of 27128978 is about 5208.5485502201. The cubic root of 27128978 is about 300.4769376627.

The spelling of 27128978 in words is "twenty-seven million, one hundred twenty-eight thousand, nine hundred seventy-eight".