21654560 has 48 divisors (see below), whose sum is σ = 52422552. Its totient is φ = 8448000.

The previous prime is 21654559. The next prime is 21654599. The reversal of 21654560 is 6545612.

It can be written as a sum of positive squares in 4 ways, for example, as 8317456 + 13337104 = 2884^2 + 3652^2 .

It is a zygodrome in base 9.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4910 + ... + 8210.

Almost surely, 2^21654560 is an apocalyptic number.

21654560 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 21654560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26211276).

21654560 is an abundant number, since it is smaller than the sum of its proper divisors (30767992).

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

21654560 is a wasteful number, since it uses less digits than its factorization.

21654560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3357 (or 3349 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 21654560 is about 4653.4460349294. The cubic root of 21654560 is about 278.7296190532.

The spelling of 21654560 in words is "twenty-one million, six hundred fifty-four thousand, five hundred sixty".