20505208 has 8 divisors (see below), whose sum is σ = 38447280. Its totient is φ = 10252600.

The previous prime is 20505203. The next prime is 20505209. The reversal of 20505208 is 80250502.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1281568 + ... + 1281583.

It is an arithmetic number, because the mean of its divisors is an integer number (4805910).

Almost surely, 2^20505208 is an apocalyptic number.

It is an amenable number.

20505208 is a deficient number, since it is larger than the sum of its proper divisors (17942072).

20505208 is a wasteful number, since it uses less digits than its factorization.

20505208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2563157 (or 2563153 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 20505208 is about 4528.2676599335. The cubic root of 20505208 is about 273.7083582399.

The spelling of 20505208 in words is "twenty million, five hundred five thousand, two hundred eight".