20685312 has 90 divisors (see below), whose sum is σ = 60603543. Its totient is φ = 6792192.

The previous prime is 20685307. The next prime is 20685337. The reversal of 20685312 is 21358602.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 10342656 + 10342656 = 3216^2 + 3216^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3216.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 308703 + ... + 308769.

Almost surely, 2^20685312 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 20685312

20685312 is an abundant number, since it is smaller than the sum of its proper divisors (39918231).

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

20685312 is an frugal number, since it uses more digits than its factorization.

20685312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 20685312 is about 4548.1108165919. The cubic root of 20685312 is about 274.5073803345.

The spelling of 20685312 in words is "twenty million, six hundred eighty-five thousand, three hundred twelve".