20388312 has 72 divisors (see below), whose sum is σ = 64244700. Its totient is φ = 5824224.

The previous prime is 20388307. The next prime is 20388323. The reversal of 20388312 is 21388302.

It is a tau number, because it is divible by the number of its divisors (72).

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 17 ways as a sum of consecutive naturals, for example, 639 + ... + 6417.

Almost surely, 2^20388312 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 20388312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32122350).

20388312 is an abundant number, since it is smaller than the sum of its proper divisors (43856388).

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

20388312 is a wasteful number, since it uses less digits than its factorization.

20388312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5805 (or 5791 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20388312 is about 4515.3418475238. The cubic root of 20388312 is about 273.1872482646.

The spelling of 20388312 in words is "twenty million, three hundred eighty-eight thousand, three hundred twelve".