13920 has 48 divisors (see below), whose sum is σ = 45360. Its totient is φ = 3584.
The previous prime is 13913. The next prime is 13921. The reversal of 13920 is 2931.
It is a tau number, because it is divible by the number of its divisors (48).
It is a Harshad number since it is a multiple of its sum of digits (15).
13920 is an undulating number in base 12.
It is a self number, because there is not a number n which added to its sum of digits gives 13920.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (13921) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 466 + ... + 494.
It is an arithmetic number, because the mean of its divisors is an integer number (945).
213920 is an apocalyptic number.
13920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 13920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680).
13920 is an abundant number, since it is smaller than the sum of its proper divisors (31440).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
13920 is a wasteful number, since it uses less digits than its factorization.
13920 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 47 (or 39 counting only the distinct ones).
The product of its (nonzero) digits is 54, while the sum is 15.
The square root of 13920 is about 117.9830496300. The cubic root of 13920 is about 24.0554274486.
The spelling of 13920 in words is "thirteen thousand, nine hundred twenty".
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.071 sec. • engine limits •