20389120 has 72 divisors (see below), whose sum is σ = 51766344. Its totient is φ = 7667712.

The previous prime is 20389111. The next prime is 20389129. The reversal of 20389120 is 2198302.

It is an interprime number because it is at equal distance from previous prime (20389111) and next prime (20389129).

It can be written as a sum of positive squares in 4 ways, for example, as 746496 + 19642624 = 864^2 + 4432^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20389129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21292 + ... + 22228.

It is an arithmetic number, because the mean of its divisors is an integer number (718977).

Almost surely, 2^20389120 is an apocalyptic number.

20389120 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 20389120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25883172).

20389120 is an abundant number, since it is smaller than the sum of its proper divisors (31377224).

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

20389120 is an equidigital number, since it uses as much as digits as its factorization.

20389120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975 (or 961 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 20389120 is about 4515.4313193758. The cubic root of 20389120 is about 273.1908570704.

The spelling of 20389120 in words is "twenty million, three hundred eighty-nine thousand, one hundred twenty".