20321221213 has 4 divisors (see below), whose sum is σ = 20352630240. Its totient is φ = 20289812188.

The previous prime is 20321221187. The next prime is 20321221229. The reversal of 20321221213 is 31212212302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31212212302 = 2 ⋅15606106151.

It is a cyclic number.

It is not a de Polignac number, because 20321221213 - 2⁹ = 20321220701 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 (20321221273) 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, 15703543 + ... + 15704836.

It is an arithmetic number, because the mean of its divisors is an integer number (5088157560).

Almost surely, 2^20321221213 is an apocalyptic number.

It is an amenable number.

20321221213 is a deficient number, since it is larger than the sum of its proper divisors (31409027).

20321221213 is an equidigital number, since it uses as much as digits as its factorization.

20321221213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31409026.

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

Adding to 20321221213 its reverse (31212212302), we get a palindrome (51533433515).

The spelling of 20321221213 in words is "twenty billion, three hundred twenty-one million, two hundred twenty-one thousand, two hundred thirteen".