20312221213 has 4 divisors (see below), whose sum is σ = 20645208508. Its totient is φ = 19979233920.

The previous prime is 20312221207. The next prime is 20312221217. The reversal of 20312221213 is 31212221302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31212221302 = 2 ⋅15606110651.

It can be written as a sum of positive squares in 2 ways, for example, as 614940804 + 19697280409 = 24798^2 + 140347^2 .

It is a cyclic number.

It is not a de Polignac number, because 20312221213 - 2⁹ = 20312220701 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 (20312221217) 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, 166493556 + ... + 166493677.

It is an arithmetic number, because the mean of its divisors is an integer number (5161302127).

Almost surely, 2^20312221213 is an apocalyptic number.

It is an amenable number.

20312221213 is a deficient number, since it is larger than the sum of its proper divisors (332987295).

20312221213 is an equidigital number, since it uses as much as digits as its factorization.

20312221213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332987294.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 20312221213 its reverse (31212221302), we get a palindrome (51524442515).

The spelling of 20312221213 in words is "twenty billion, three hundred twelve million, two hundred twenty-one thousand, two hundred thirteen".