20531313205 has 16 divisors (see below), whose sum is σ = 26967742704. Its totient is φ = 14913031680.

The previous prime is 20531313191. The next prime is 20531313221. The reversal of 20531313205 is 50231313502.

It can be written as a sum of positive squares in 8 ways, for example, as 1528966404 + 19002346801 = 39102^2 + 137849^2 .

It is not a de Polignac number, because 20531313205 - 2¹⁵ = 20531280437 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20531313205.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2585104 + ... + 2593033.

It is an arithmetic number, because the mean of its divisors is an integer number (1685483919).

Almost surely, 2^20531313205 is an apocalyptic number.

It is an amenable number.

20531313205 is a deficient number, since it is larger than the sum of its proper divisors (6436429499).

20531313205 is a wasteful number, since it uses less digits than its factorization.

20531313205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5178216.

The product of its (nonzero) digits is 2700, while the sum is 25.

Adding to 20531313205 its reverse (50231313502), we get a palindrome (70762626707).

The spelling of 20531313205 in words is "twenty billion, five hundred thirty-one million, three hundred thirteen thousand, two hundred five".