20512500 has 72 divisors (see below), whose sum is σ = 59933664. Its totient is φ = 5460000.

The previous prime is 20512487. The next prime is 20512501. The reversal of 20512500 is 521502.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20512500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20512501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37227 + ... + 37773.

It is an arithmetic number, because the mean of its divisors is an integer number (832412).

Almost surely, 2^20512500 is an apocalyptic number.

20512500 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 20512500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29966832).

20512500 is an abundant number, since it is smaller than the sum of its proper divisors (39421164).

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

20512500 is an equidigital number, since it uses as much as digits as its factorization.

20512500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 20512500 is about 4529.0727527828. The cubic root of 20512500 is about 273.7407995073.

It can be divided in two parts, 20512 and 500, that added together give a palindrome (21012).

The spelling of 20512500 in words is "twenty million, five hundred twelve thousand, five hundred".