20500505 has 8 divisors (see below), whose sum is σ = 24707592. Its totient is φ = 16329088.

The previous prime is 20500483. The next prime is 20500511. The reversal of 20500505 is 50500502.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 456976 + 20043529 = 676^2 + 4477^2 .

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 20500505 - 2¹⁰ = 20499481 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7634 + ... + 9963.

It is an arithmetic number, because the mean of its divisors is an integer number (3088449).

Almost surely, 2^20500505 is an apocalyptic number.

It is an amenable number.

20500505 is a deficient number, since it is larger than the sum of its proper divisors (4207087).

20500505 is a wasteful number, since it uses less digits than its factorization.

20500505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17835.

The product of its (nonzero) digits is 250, while the sum is 17.

The square root of 20500505 is about 4527.7483366459. The cubic root of 20500505 is about 273.6874310551.

The spelling of 20500505 in words is "twenty million, five hundred thousand, five hundred five".