27973565 has 4 divisors (see below), whose sum is σ = 33568284. Its totient is φ = 22378848.

The previous prime is 27973553. The next prime is 27973657. The reversal of 27973565 is 56537972.

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 8375236 + 19598329 = 2894^2 + 4427^2 .

It is a cyclic number.

It is not a de Polignac number, because 27973565 - 2⁴ = 27973549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2797352 + ... + 2797361.

It is an arithmetic number, because the mean of its divisors is an integer number (8392071).

Almost surely, 2^27973565 is an apocalyptic number.

It is an amenable number.

27973565 is a deficient number, since it is larger than the sum of its proper divisors (5594719).

27973565 is an equidigital number, since it uses as much as digits as its factorization.

27973565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5594718.

The product of its digits is 396900, while the sum is 44.

The square root of 27973565 is about 5289.0041595748. The cubic root of 27973565 is about 303.5633049202.

Subtracting from 27973565 its sum of digits (44), we obtain a square (27973521 = 5289²).

The spelling of 27973565 in words is "twenty-seven million, nine hundred seventy-three thousand, five hundred sixty-five".