20440140 has 96 divisors (see below), whose sum is σ = 67060224. Its totient is φ = 4554240.

The previous prime is 20440111. The next prime is 20440151. The reversal of 20440140 is 4104402.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16627 + ... + 17813.

It is an arithmetic number, because the mean of its divisors is an integer number (698544).

Almost surely, 2^20440140 is an apocalyptic number.

20440140 is a gapful number since it is divisible by the number (20) 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 20440140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33530112).

20440140 is an abundant number, since it is smaller than the sum of its proper divisors (46620084).

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

20440140 is a wasteful number, since it uses less digits than its factorization.

20440140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1247 (or 1245 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 20440140 is about 4521.0773052448. The cubic root of 20440140 is about 273.4185371231.

Adding to 20440140 its reverse (4104402), we get a palindrome (24544542).

The spelling of 20440140 in words is "twenty million, four hundred forty thousand, one hundred forty".