20312313012221 has 4 divisors (see below), whose sum is σ = 20312325668700. Its totient is φ = 20312300355744.

The previous prime is 20312313012197. The next prime is 20312313012227. The reversal of 20312313012221 is 12221031321302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18523219507321 + 1789093504900 = 4303861^2 + 1337570^2 .

It is a cyclic number.

It is not a de Polignac number, because 20312313012221 - 2²² = 20312308817917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312313012227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3499376 + ... + 7271193.

It is an arithmetic number, because the mean of its divisors is an integer number (5078081417175).

Almost surely, 2^{20312313012221} is an apocalyptic number.

It is an amenable number.

20312313012221 is a deficient number, since it is larger than the sum of its proper divisors (12656479).

20312313012221 is a wasteful number, since it uses less digits than its factorization.

20312313012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12656478.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 20312313012221 its reverse (12221031321302), we get a palindrome (32533344333523).

The spelling of 20312313012221 in words is "twenty trillion, three hundred twelve billion, three hundred thirteen million, twelve thousand, two hundred twenty-one".