20641005 has 144 divisors (see below), whose sum is σ = 48657024. Its totient is φ = 7983360.

The previous prime is 20641001. The next prime is 20641007. The reversal of 20641005 is 50014602.

It is a happy number.

20641005 is a `hidden beast` number, since 20 + 641 + 0 + 0 + 5 = 666.

It is not a de Polignac number, because 20641005 - 2² = 20641001 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20641001) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 557847 + ... + 557883.

It is an arithmetic number, because the mean of its divisors is an integer number (337896).

Almost surely, 2^20641005 is an apocalyptic number.

It is an amenable number.

20641005 is an abundant number, since it is smaller than the sum of its proper divisors (28016019).

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

20641005 is a wasteful number, since it uses less digits than its factorization.

20641005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20641005 is about 4543.2372819389. The cubic root of 20641005 is about 274.3112461120.

Adding to 20641005 its reverse (50014602), we get a palindrome (70655607).

The spelling of 20641005 in words is "twenty million, six hundred forty-one thousand, five".