27688645 has 8 divisors (see below), whose sum is σ = 33555960. Its totient is φ = 21931200.

The previous prime is 27688627. The next prime is 27688657. The reversal of 27688645 is 54688672.

It is a Cunningham number, because it is equal to 5262²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 5116644 + 22572001 = 2262^2 + 4751^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 27688645 - 2¹¹ = 27686597 is a prime.

It is a super-2 number, since 2×27688645² = 1533322123872050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 27688595 and 27688604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26910 + ... + 27919.

It is an arithmetic number, because the mean of its divisors is an integer number (4194495).

Almost surely, 2^27688645 is an apocalyptic number.

It is an amenable number.

27688645 is a deficient number, since it is larger than the sum of its proper divisors (5867315).

27688645 is a wasteful number, since it uses less digits than its factorization.

27688645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54935.

The product of its digits is 645120, while the sum is 46.

The square root of 27688645 is about 5262.0000950209. Note that the first 4 decimals coincide. The cubic root of 27688645 is about 302.5291550343.

The spelling of 27688645 in words is "twenty-seven million, six hundred eighty-eight thousand, six hundred forty-five".