20665312 has 48 divisors (see below), whose sum is σ = 43923600. Its totient is φ = 9538560.

The previous prime is 20665297. The next prime is 20665357. The reversal of 20665312 is 21356602.

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 7 ways as a sum of consecutive naturals, for example, 24514 + ... + 25342.

It is an arithmetic number, because the mean of its divisors is an integer number (915075).

Almost surely, 2^20665312 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 20665312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21961800).

20665312 is an abundant number, since it is smaller than the sum of its proper divisors (23258288).

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

20665312 is a wasteful number, since it uses less digits than its factorization.

20665312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899 (or 891 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20665312 is about 4545.9115697514. The cubic root of 20665312 is about 274.4188808559.

The spelling of 20665312 in words is "twenty million, six hundred sixty-five thousand, three hundred twelve".