20658816 has 96 divisors (see below), whose sum is σ = 60465600. Its totient is φ = 6769152.

The previous prime is 20658779. The next prime is 20658821. The reversal of 20658816 is 61885602.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 11 ways as a sum of consecutive naturals, for example, 90895 + ... + 91121.

It is an arithmetic number, because the mean of its divisors is an integer number (629850).

Almost surely, 2^20658816 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 20658816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30232800).

20658816 is an abundant number, since it is smaller than the sum of its proper divisors (39806784).

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

20658816 is a wasteful number, since it uses less digits than its factorization.

20658816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 20658816 is about 4545.1970254325. The cubic root of 20658816 is about 274.3901239408.

The spelling of 20658816 in words is "twenty million, six hundred fifty-eight thousand, eight hundred sixteen".