20012500 has 36 divisors (see below), whose sum is σ = 43801884. Its totient is φ = 8000000.

The previous prime is 20012479. The next prime is 20012543. The reversal of 20012500 is 521002.

It can be written as a sum of positive squares in 6 ways, for example, as 9746884 + 10265616 = 3122^2 + 3204^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 11700 + ... + 13300.

It is an arithmetic number, because the mean of its divisors is an integer number (1216719).

Almost surely, 2^20012500 is an apocalyptic number.

20012500 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 20012500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21900942).

20012500 is an abundant number, since it is smaller than the sum of its proper divisors (23789384).

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

20012500 is an equidigital number, since it uses as much as digits as its factorization.

20012500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1630 (or 1608 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 10.

The square root of 20012500 is about 4473.5332791877. The cubic root of 20012500 is about 271.4983002493.

Adding to 20012500 its reverse (521002), we get a palindrome (20533502).

The spelling of 20012500 in words is "twenty million, twelve thousand, five hundred".