20712500 has 36 divisors (see below), whose sum is σ = 45333036. Its totient is φ = 8280000.

The previous prime is 20712499. The next prime is 20712521. The reversal of 20712500 is 521702.

It can be written as a sum of positive squares in 6 ways, for example, as 18438436 + 2274064 = 4294^2 + 1508^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11672 + ... + 13328.

It is an arithmetic number, because the mean of its divisors is an integer number (1259251).

Almost surely, 2^20712500 is an apocalyptic number.

20712500 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 20712500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22666518).

20712500 is an abundant number, since it is smaller than the sum of its proper divisors (24620536).

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

20712500 is an equidigital number, since it uses as much as digits as its factorization.

20712500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1686 (or 1664 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 20712500 is about 4551.0987684294. The cubic root of 20712500 is about 274.6275950906.

It can be divided in two parts, 20712 and 500, that added together give a palindrome (21212).

The spelling of 20712500 in words is "twenty million, seven hundred twelve thousand, five hundred".