17720 has 16 divisors (see below), whose sum is σ = 39960. Its totient is φ = 7072.

The previous prime is 17713. The next prime is 17729. The reversal of 17720 is 2771.

It is a happy number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17729) by changing a digit.

17720 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182 + ... + 261.

2¹⁷⁷²⁰ is an apocalyptic number.

17720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

17720 is an abundant number, since it is smaller than the sum of its proper divisors (22240).

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 (19980).

17720 is a wasteful number, since it uses less digits than its factorization.

17720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 450 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 17.

The square root of 17720 is about 133.1164903383. The cubic root of 17720 is about 26.0708128781.

It can be divided in two parts, 17 and 720, that added together give a palindrome (737).

The spelling of 17720 in words is "seventeen thousand, seven hundred twenty", and thus it is an iban number.