20044640 has 96 divisors (see below), whose sum is σ = 59076864. Its totient is φ = 6243840.

The previous prime is 20044637. The next prime is 20044657. The reversal of 20044640 is 4644002.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11507 + ... + 13133.

It is an arithmetic number, because the mean of its divisors is an integer number (615384).

Almost surely, 2^20044640 is an apocalyptic number.

20044640 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 20044640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29538432).

20044640 is an abundant number, since it is smaller than the sum of its proper divisors (39032224).

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

20044640 is a wasteful number, since it uses less digits than its factorization.

20044640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660 (or 1652 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 20044640 is about 4477.1240769047. The cubic root of 20044640 is about 271.6435642634.

Adding to 20044640 its reverse (4644002), we get a palindrome (24688642).

The spelling of 20044640 in words is "twenty million, forty-four thousand, six hundred forty".