20745216 has 66 divisors (see below), whose sum is σ = 59927972. Its totient is φ = 6912000.

The previous prime is 20745211. The next prime is 20745217. The reversal of 20745216 is 61254702.

20745216 is a `hidden beast` number, since 207 + 452 + 1 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20745216.

It is not an unprimeable number, because it can be changed into a prime (20745211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8091 + ... + 10341.

Almost surely, 2^20745216 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 20745216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29963986).

20745216 is an abundant number, since it is smaller than the sum of its proper divisors (39182756).

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

20745216 is a wasteful number, since it uses less digits than its factorization.

20745216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277 (or 2256 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 20745216 is about 4554.6916470822. The cubic root of 20745216 is about 274.7721131354.

Adding to 20745216 its reverse (61254702), we get a palindrome (81999918).

The spelling of 20745216 in words is "twenty million, seven hundred forty-five thousand, two hundred sixteen".