20397312 has 144 divisors (see below), whose sum is σ = 65244480. Its totient is φ = 6248448.

The previous prime is 20397269. The next prime is 20397313. The reversal of 20397312 is 21379302.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20397313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89743 + ... + 89969.

Almost surely, 2^20397312 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 20397312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32622240).

20397312 is an abundant number, since it is smaller than the sum of its proper divisors (44847168).

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

20397312 is a wasteful number, since it uses less digits than its factorization.

20397312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 245 counting only the distinct ones).

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

The square root of 20397312 is about 4516.3383398501. The cubic root of 20397312 is about 273.2274399774.

The spelling of 20397312 in words is "twenty million, three hundred ninety-seven thousand, three hundred twelve".