27564381 has 20 divisors (see below), whose sum is σ = 44345532. Its totient is φ = 16962048.

The previous prime is 27564353. The next prime is 27564391. The reversal of 27564381 is 18346572.

27564381 is a `hidden beast` number, since 2 + 7 + 5 + 643 + 8 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16475481 + 11088900 = 4059^2 + 3330^2 .

It is not a de Polignac number, because 27564381 - 2⁵ = 27564349 is a prime.

It is a super-2 number, since 2×27564381² = 1519590199826322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27564311) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 12036 + ... + 14141.

Almost surely, 2^27564381 is an apocalyptic number.

It is an amenable number.

27564381 is a deficient number, since it is larger than the sum of its proper divisors (16781151).

27564381 is a wasteful number, since it uses less digits than its factorization.

27564381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26202 (or 26193 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 27564381 is about 5250.1791398009. The cubic root of 27564381 is about 302.0759022994.

The spelling of 27564381 in words is "twenty-seven million, five hundred sixty-four thousand, three hundred eighty-one".