27555381 has 12 divisors (see below), whose sum is σ = 45488352. Its totient is φ = 15745896.

The previous prime is 27555371. The next prime is 27555391. The reversal of 27555381 is 18355572.

27555381 is a `hidden beast` number, since 27 + 5 + 553 + 81 = 666.

It is an interprime number because it is at equal distance from previous prime (27555371) and next prime (27555391).

It is not a de Polignac number, because 27555381 - 2²¹ = 25458229 is a prime.

It is a super-2 number, since 2×27555381² = 1518598044110322, 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 (27555361) 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 11 ways as a sum of consecutive naturals, for example, 218631 + ... + 218756.

It is an arithmetic number, because the mean of its divisors is an integer number (3790696).

Almost surely, 2^27555381 is an apocalyptic number.

27555381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27555381 is a deficient number, since it is larger than the sum of its proper divisors (17932971).

27555381 is a wasteful number, since it uses less digits than its factorization.

27555381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437400 (or 437397 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 27555381 is about 5249.3219562149. The cubic root of 27555381 is about 302.0430219545.

The spelling of 27555381 in words is "twenty-seven million, five hundred fifty-five thousand, three hundred eighty-one".