21238560 has 288 divisors, whose sum is σ = 86486400. Its totient is φ = 4741632.

The previous prime is 21238549. The next prime is 21238571. The reversal of 21238560 is 6583212.

It is an interprime number because it is at equal distance from previous prime (21238549) and next prime (21238571).

It is a tau number, because it is divible by the number of its divisors (288).

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 47 ways as a sum of consecutive naturals, for example, 493899 + ... + 493941.

It is an arithmetic number, because the mean of its divisors is an integer number (300300).

Almost surely, 2^21238560 is an apocalyptic number.

21238560 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 21238560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43243200).

21238560 is an abundant number, since it is smaller than the sum of its proper divisors (65247840).

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

21238560 is a wasteful number, since it uses less digits than its factorization.

21238560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21238560 is about 4608.5312193800. The cubic root of 21238560 is about 276.9331990602.

The spelling of 21238560 in words is "twenty-one million, two hundred thirty-eight thousand, five hundred sixty".