21850560 has 168 divisors, whose sum is σ = 78217776. Its totient is φ = 5806080.

The previous prime is 21850547. The next prime is 21850573. The reversal of 21850560 is 6505812.

21850560 is a `hidden beast` number, since 21 + 85 + 0 + 560 = 666.

It is an interprime number because it is at equal distance from previous prime (21850547) and next prime (21850573).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77620 + ... + 77900.

It is an arithmetic number, because the mean of its divisors is an integer number (465582).

Almost surely, 2^21850560 is an apocalyptic number.

21850560 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 21850560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39108888).

21850560 is an abundant number, since it is smaller than the sum of its proper divisors (56367216).

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

21850560 is an equidigital number, since it uses as much as digits as its factorization.

21850560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 21850560 is about 4674.4582573813. The cubic root of 21850560 is about 279.5680414393.

The spelling of 21850560 in words is "twenty-one million, eight hundred fifty thousand, five hundred sixty".