20003520 has 112 divisors (see below), whose sum is σ = 64666368. Its totient is φ = 5237760.

The previous prime is 20003513. The next prime is 20003521. The reversal of 20003520 is 2530002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 20003496 and 20003505.

It is not an unprimeable number, because it can be changed into a prime (20003521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64165 + ... + 64475.

Almost surely, 2^20003520 is an apocalyptic number.

20003520 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 20003520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32333184).

20003520 is an abundant number, since it is smaller than the sum of its proper divisors (44662848).

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

20003520 is a wasteful number, since it uses less digits than its factorization.

20003520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398 (or 388 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 12.

The square root of 20003520 is about 4472.5294856490. The cubic root of 20003520 is about 271.4576853087.

Adding to 20003520 its reverse (2530002), we get a palindrome (22533522).

The spelling of 20003520 in words is "twenty million, three thousand, five hundred twenty".