20709306 has 48 divisors (see below), whose sum is σ = 47010600. Its totient is φ = 6580224.

The previous prime is 20709289. The next prime is 20709319. The reversal of 20709306 is 60390702.

It can be written as a sum of positive squares in 4 ways, for example, as 20169081 + 540225 = 4491^2 + 735^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20709306.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50430 + ... + 50838.

Almost surely, 2^20709306 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20709306, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23505300).

20709306 is an abundant number, since it is smaller than the sum of its proper divisors (26301294).

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

20709306 is a wasteful number, since it uses less digits than its factorization.

20709306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 20709306 is about 4550.7478506285. The cubic root of 20709306 is about 274.6134779209.

The spelling of 20709306 in words is "twenty million, seven hundred nine thousand, three hundred six".