27905645 has 4 divisors (see below), whose sum is σ = 33486780. Its totient is φ = 22324512.

The previous prime is 27905629. The next prime is 27905671. The reversal of 27905645 is 54650972.

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 12687844 + 15217801 = 3562^2 + 3901^2 .

It is a cyclic number.

It is not a de Polignac number, because 27905645 - 2⁴ = 27905629 is a prime.

It is a super-3 number, since 3×27905645³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 27905599 and 27905608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2790560 + ... + 2790569.

It is an arithmetic number, because the mean of its divisors is an integer number (8371695).

Almost surely, 2^27905645 is an apocalyptic number.

It is an amenable number.

27905645 is a deficient number, since it is larger than the sum of its proper divisors (5581135).

27905645 is an equidigital number, since it uses as much as digits as its factorization.

27905645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5581134.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 27905645 is about 5282.5793888971. The cubic root of 27905645 is about 303.3174212426.

The spelling of 27905645 in words is "twenty-seven million, nine hundred five thousand, six hundred forty-five".