27780385 has 4 divisors (see below), whose sum is σ = 33336468. Its totient is φ = 22224304.

The previous prime is 27780373. The next prime is 27780391. The reversal of 27780385 is 58308772.

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 10863616 + 16916769 = 3296^2 + 4113^2 .

It is a cyclic number.

It is not a de Polignac number, because 27780385 - 2¹¹ = 27778337 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2778034 + ... + 2778043.

It is an arithmetic number, because the mean of its divisors is an integer number (8334117).

Almost surely, 2^27780385 is an apocalyptic number.

It is an amenable number.

27780385 is a deficient number, since it is larger than the sum of its proper divisors (5556083).

27780385 is an equidigital number, since it uses as much as digits as its factorization.

27780385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5556082.

The product of its (nonzero) digits is 94080, while the sum is 40.

The square root of 27780385 is about 5270.7101039613. The cubic root of 27780385 is about 302.8629071166.

The spelling of 27780385 in words is "twenty-seven million, seven hundred eighty thousand, three hundred eighty-five".