21189120 has 160 divisors (see below), whose sum is σ = 70709760. Its totient is φ = 5406720.

The previous prime is 21189109. The next prime is 21189131. The reversal of 21189120 is 2198112.

It is an interprime number because it is at equal distance from previous prime (21189109) and next prime (21189131).

It is a tau number, because it is divible by the number of its divisors (160).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238036 + ... + 238124.

It is an arithmetic number, because the mean of its divisors is an integer number (441936).

Almost surely, 2^21189120 is an apocalyptic number.

21189120 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 21189120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35354880).

21189120 is an abundant number, since it is smaller than the sum of its proper divisors (49520640).

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

21189120 is an equidigital number, since it uses as much as digits as its factorization.

21189120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 21189120 is about 4603.1641291616. The cubic root of 21189120 is about 276.7181465792.

The spelling of 21189120 in words is "twenty-one million, one hundred eighty-nine thousand, one hundred twenty".