27966561 has 16 divisors (see below), whose sum is σ = 43768704. Its totient is φ = 15548544.

The previous prime is 27966541. The next prime is 27966569. The reversal of 27966561 is 16566972.

It is not a de Polignac number, because 27966561 - 2⁵ = 27966529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (27966569) 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 15 ways as a sum of consecutive naturals, for example, 17220 + ... + 18773.

It is an arithmetic number, because the mean of its divisors is an integer number (2735544).

Almost surely, 2^27966561 is an apocalyptic number.

27966561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

27966561 is a deficient number, since it is larger than the sum of its proper divisors (15802143).

27966561 is a wasteful number, since it uses less digits than its factorization.

27966561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36040.

The product of its digits is 136080, while the sum is 42.

The square root of 27966561 is about 5288.3419896977. The cubic root of 27966561 is about 303.5379674887.

The spelling of 27966561 in words is "twenty-seven million, nine hundred sixty-six thousand, five hundred sixty-one".