20505102201 has 12 divisors (see below), whose sum is σ = 29666493012. Its totient is φ = 13647908736.

The previous prime is 20505102193. The next prime is 20505102227. The reversal of 20505102201 is 10220150502.

It can be written as a sum of positive squares in 2 ways, for example, as 3780405225 + 16724696976 = 61485^2 + 129324^2 .

It is not a de Polignac number, because 20505102201 - 2³ = 20505102193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20505102281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1840756 + ... + 1851861.

It is an arithmetic number, because the mean of its divisors is an integer number (2472207751).

Almost surely, 2^20505102201 is an apocalyptic number.

It is an amenable number.

20505102201 is a deficient number, since it is larger than the sum of its proper divisors (9161390811).

20505102201 is a wasteful number, since it uses less digits than its factorization.

20505102201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693240 (or 3693237 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

Adding to 20505102201 its reverse (10220150502), we get a palindrome (30725252703).

The spelling of 20505102201 in words is "twenty billion, five hundred five million, one hundred two thousand, two hundred one".