20812505 has 48 divisors (see below), whose sum is σ = 32503680. Its totient is φ = 12676608.

The previous prime is 20812483. The next prime is 20812511. The reversal of 20812505 is 50521802.

It is not a de Polignac number, because 20812505 - 2²⁰ = 19763929 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79004 + ... + 79266.

It is an arithmetic number, because the mean of its divisors is an integer number (677160).

Almost surely, 2^20812505 is an apocalyptic number.

It is an amenable number.

20812505 is a deficient number, since it is larger than the sum of its proper divisors (11691175).

20812505 is a wasteful number, since it uses less digits than its factorization.

20812505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 20812505 is about 4562.0724457203. The cubic root of 20812505 is about 275.0688753103.

The spelling of 20812505 in words is "twenty million, eight hundred twelve thousand, five hundred five".