20648905 has 8 divisors (see below), whose sum is σ = 24822792. Its totient is φ = 16489728.

The previous prime is 20648893. The next prime is 20648909. The reversal of 20648905 is 50984602.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 28224 + 20620681 = 168^2 + 4541^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20648905 - 2¹³ = 20640713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20648909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 304 + ... + 6433.

It is an arithmetic number, because the mean of its divisors is an integer number (3102849).

Almost surely, 2^20648905 is an apocalyptic number.

It is an amenable number.

20648905 is a deficient number, since it is larger than the sum of its proper divisors (4173887).

20648905 is an equidigital number, since it uses as much as digits as its factorization.

20648905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7355.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20648905 is about 4544.1066228688. The cubic root of 20648905 is about 274.3462376645.

The spelling of 20648905 in words is "twenty million, six hundred forty-eight thousand, nine hundred five".