21625560 has 192 divisors, whose sum is σ = 79073280. Its totient is φ = 5080320.

The previous prime is 21625559. The next prime is 21625577. The reversal of 21625560 is 6552612.

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, 170217 + ... + 170343.

It is an arithmetic number, because the mean of its divisors is an integer number (411840).

Almost surely, 2^21625560 is an apocalyptic number.

21625560 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 21625560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39536640).

21625560 is an abundant number, since it is smaller than the sum of its proper divisors (57447720).

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

21625560 is a wasteful number, since it uses less digits than its factorization.

21625560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 191 counting only the distinct ones).

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

The square root of 21625560 is about 4650.3290206178. The cubic root of 21625560 is about 278.6051376509.

The spelling of 21625560 in words is "twenty-one million, six hundred twenty-five thousand, five hundred sixty".