20688750 has 80 divisors (see below), whose sum is σ = 57544080. Its totient is φ = 5508000.

The previous prime is 20688727. The next prime is 20688751. The reversal of 20688750 is 5788602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20688751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 33444 + ... + 34056.

It is an arithmetic number, because the mean of its divisors is an integer number (719301).

Almost surely, 2^20688750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20688750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28772040).

20688750 is an abundant number, since it is smaller than the sum of its proper divisors (36855330).

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

20688750 is an equidigital number, since it uses as much as digits as its factorization.

20688750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 20688750 is about 4548.4887600169. The cubic root of 20688750 is about 274.5225876483.

The spelling of 20688750 in words is "twenty million, six hundred eighty-eight thousand, seven hundred fifty".