100440 has 80 divisors (see below), whose sum is σ = 348480. Its totient is φ = 25920.

The previous prime is 100417. The next prime is 100447. The reversal of 100440 is 44001.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100447) by changing a digit.

100440 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 19 ways as a sum of consecutive naturals, for example, 3225 + ... + 3255.

It is an arithmetic number, because the mean of its divisors is an integer number (4356).

2¹⁰⁰⁴⁴⁰ is an apocalyptic number.

100440 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 100440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174240).

100440 is an abundant number, since it is smaller than the sum of its proper divisors (248040).

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

100440 is a wasteful number, since it uses less digits than its factorization.

100440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 100440 is about 316.9227035099. The cubic root of 100440 is about 46.4838653700.

Adding to 100440 its reverse (44001), we get a palindrome (144441).

The spelling of 100440 in words is "one hundred thousand, four hundred forty", and thus it is an iban number.