20641408 has 32 divisors (see below), whose sum is σ = 41469120. Its totient is φ = 10233600.

The previous prime is 20641403. The next prime is 20641457. The reversal of 20641408 is 80414602.

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (20641403) 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, 16153 + ... + 17383.

It is an arithmetic number, because the mean of its divisors is an integer number (1295910).

Almost surely, 2^20641408 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 20641408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20734560).

20641408 is an abundant number, since it is smaller than the sum of its proper divisors (20827712).

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

20641408 is a wasteful number, since it uses less digits than its factorization.

20641408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376 (or 1364 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 20641408 is about 4543.2816333571. The cubic root of 20641408 is about 274.3130313402.

It can be divided in two parts, 206 and 41408, that added together give a palindrome (41614).

The spelling of 20641408 in words is "twenty million, six hundred forty-one thousand, four hundred eight".