20391360 has 112 divisors (see below), whose sum is σ = 70664832. Its totient is φ = 4940800.

The previous prime is 20391353. The next prime is 20391361. The reversal of 20391360 is 6319302.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20391360.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20391361) 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, 9595 + ... + 11525.

It is an arithmetic number, because the mean of its divisors is an integer number (630936).

Almost surely, 2^20391360 is an apocalyptic number.

20391360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20391360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35332416).

20391360 is an abundant number, since it is smaller than the sum of its proper divisors (50273472).

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

20391360 is a wasteful number, since it uses less digits than its factorization.

20391360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962 (or 1952 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 24.

The square root of 20391360 is about 4515.6793508840. The cubic root of 20391360 is about 273.2008611823.

The spelling of 20391360 in words is "twenty million, three hundred ninety-one thousand, three hundred sixty".