27780 has 24 divisors (see below), whose sum is σ = 77952. Its totient is φ = 7392.

The previous prime is 27779. The next prime is 27791. The reversal of 27780 is 8772.

It is a self number, because there is not a number n which added to its sum of digits gives 27780.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172 + ... + 291.

It is an arithmetic number, because the mean of its divisors is an integer number (3248).

2²⁷⁷⁸⁰ is an apocalyptic number.

27780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

27780 is an abundant number, since it is smaller than the sum of its proper divisors (50172).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38976).

27780 is a wasteful number, since it uses less digits than its factorization.

27780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 24.

The square root of 27780 is about 166.6733332000. The cubic root of 27780 is about 30.2861508015.

The spelling of 27780 in words is "twenty-seven thousand, seven hundred eighty".