20709472 has 48 divisors (see below), whose sum is σ = 47416320. Its totient is φ = 8719488.

The previous prime is 20709467. The next prime is 20709473. The reversal of 20709472 is 27490702.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20709473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12433 + ... + 13999.

It is an arithmetic number, because the mean of its divisors is an integer number (987840).

Almost surely, 2^20709472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20709472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23708160).

20709472 is an abundant number, since it is smaller than the sum of its proper divisors (26706848).

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

20709472 is a wasteful number, since it uses less digits than its factorization.

20709472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643 (or 1635 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 20709472 is about 4550.7660893524. The cubic root of 20709472 is about 274.6142116606.

The spelling of 20709472 in words is "twenty million, seven hundred nine thousand, four hundred seventy-two".