27664 has 40 divisors (see below), whose sum is σ = 69440. Its totient is φ = 10368.

The previous prime is 27653. The next prime is 27673. The reversal of 27664 is 46672.

27664 = T₇ + T₈ + ... + T₅₄.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1447 + ... + 1465.

It is an arithmetic number, because the mean of its divisors is an integer number (1736).

2²⁷⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 27664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34720).

27664 is an abundant number, since it is smaller than the sum of its proper divisors (41776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27664 is a wasteful number, since it uses less digits than its factorization.

27664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47 (or 41 counting only the distinct ones).

The product of its digits is 2016, while the sum is 25.

The square root of 27664 is about 166.3249830903. The cubic root of 27664 is about 30.2439370405.

The spelling of 27664 in words is "twenty-seven thousand, six hundred sixty-four".