21189024 has 144 divisors (see below), whose sum is σ = 64864800. Its totient is φ = 6547968.

The previous prime is 21189019. The next prime is 21189041. The reversal of 21189024 is 42098112.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 359107 + ... + 359165.

It is an arithmetic number, because the mean of its divisors is an integer number (450450).

Almost surely, 2^21189024 is an apocalyptic number.

21189024 is a gapful number since it is divisible by the number (24) 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 21189024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32432400).

21189024 is an abundant number, since it is smaller than the sum of its proper divisors (43675776).

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

21189024 is a wasteful number, since it uses less digits than its factorization.

21189024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 21189024 is about 4603.1537015398. The cubic root of 21189024 is about 276.7177286763.

The spelling of 21189024 in words is "twenty-one million, one hundred eighty-nine thousand, twenty-four".