20553305 has 4 divisors (see below), whose sum is σ = 24663972. Its totient is φ = 16442640.

The previous prime is 20553301. The next prime is 20553331. The reversal of 20553305 is 50335502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9709456 + 10843849 = 3116^2 + 3293^2 .

It is not a de Polignac number, because 20553305 - 2² = 20553301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20553301) 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, 2055326 + ... + 2055335.

It is an arithmetic number, because the mean of its divisors is an integer number (6165993).

Almost surely, 2^20553305 is an apocalyptic number.

It is an amenable number.

20553305 is a deficient number, since it is larger than the sum of its proper divisors (4110667).

20553305 is an equidigital number, since it uses as much as digits as its factorization.

20553305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4110666.

The product of its (nonzero) digits is 2250, while the sum is 23.

The square root of 20553305 is about 4533.5752999151. The cubic root of 20553305 is about 273.9221945066.

Adding to 20553305 its reverse (50335502), we get a palindrome (70888807).

The spelling of 20553305 in words is "twenty million, five hundred fifty-three thousand, three hundred five".