21652560 has 240 divisors, whose sum is σ = 80954640. Its totient is φ = 5160960.

The previous prime is 21652537. The next prime is 21652639. The reversal of 21652560 is 6525612.

21652560 is a `hidden beast` number, since 2 + 1 + 652 + 5 + 6 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 968256 + 20684304 = 984^2 + 4548^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 354930 + ... + 354990.

It is an arithmetic number, because the mean of its divisors is an integer number (337311).

Almost surely, 2^21652560 is an apocalyptic number.

21652560 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 21652560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40477320).

21652560 is an abundant number, since it is smaller than the sum of its proper divisors (59302080).

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

21652560 is a wasteful number, since it uses less digits than its factorization.

21652560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 21652560 is about 4653.2311354585. The cubic root of 21652560 is about 278.7210376982.

The spelling of 21652560 in words is "twenty-one million, six hundred fifty-two thousand, five hundred sixty".