21743616 has 48 divisors (see below), whose sum is σ = 57985200. Its totient is φ = 7245824.

The previous prime is 21743611. The next prime is 21743627. The reversal of 21743616 is 61634712.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (21743611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4375 + ... + 7913.

It is an arithmetic number, because the mean of its divisors is an integer number (1208025).

Almost surely, 2^21743616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21743616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28992600).

21743616 is an abundant number, since it is smaller than the sum of its proper divisors (36241584).

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

21743616 is an equidigital number, since it uses as much as digits as its factorization.

21743616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3564 (or 3544 counting only the distinct ones).

The product of its digits is 6048, while the sum is 30.

The square root of 21743616 is about 4663.0050396713. The cubic root of 21743616 is about 279.1111952554. Note that the first 4 decimals are identical.

The spelling of 21743616 in words is "twenty-one million, seven hundred forty-three thousand, six hundred sixteen".