20213320021 has 4 divisors (see below), whose sum is σ = 20221956844. Its totient is φ = 20204683200.

The previous prime is 20213320007. The next prime is 20213320037. The reversal of 20213320021 is 12002331202.

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 5695720900 + 14517599121 = 75470^2 + 120489^2 .

It is a cyclic number.

It is not a de Polignac number, because 20213320021 - 2¹⁵ = 20213287253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20213319977 and 20213320004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213320051) 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, 4314900 + ... + 4319581.

It is an arithmetic number, because the mean of its divisors is an integer number (5055489211).

Almost surely, 2^20213320021 is an apocalyptic number.

It is an amenable number.

20213320021 is a deficient number, since it is larger than the sum of its proper divisors (8636823).

20213320021 is an equidigital number, since it uses as much as digits as its factorization.

20213320021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8636822.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 20213320021 its reverse (12002331202), we get a palindrome (32215651223).

The spelling of 20213320021 in words is "twenty billion, two hundred thirteen million, three hundred twenty thousand, twenty-one".