27128609 has 4 divisors (see below), whose sum is σ = 27165204. Its totient is φ = 27092016.

The previous prime is 27128587. The next prime is 27128623. The reversal of 27128609 is 90682172.

It is a happy number.

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 12229009 + 14899600 = 3497^2 + 3860^2 .

It is a cyclic number.

It is not a de Polignac number, because 27128609 - 2¹⁶ = 27063073 is a prime.

It is a super-2 number, since 2×27128609² = 1471922852549762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27128639) 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, 17162 + ... + 18675.

It is an arithmetic number, because the mean of its divisors is an integer number (6791301).

Almost surely, 2^27128609 is an apocalyptic number.

It is an amenable number.

27128609 is a deficient number, since it is larger than the sum of its proper divisors (36595).

27128609 is an equidigital number, since it uses as much as digits as its factorization.

27128609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36594.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 27128609 is about 5208.5131275634. The cubic root of 27128609 is about 300.4755753250.

The spelling of 27128609 in words is "twenty-seven million, one hundred twenty-eight thousand, six hundred nine".