20420020221 has 4 divisors (see below), whose sum is σ = 27226693632. Its totient is φ = 13613346812.

The previous prime is 20420020177. The next prime is 20420020223. The reversal of 20420020221 is 12202002402.

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.

It is a cyclic number.

It is not a de Polignac number, because 20420020221 - 2¹¹ = 20420018173 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20420020221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420020223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3403336701 + ... + 3403336706.

It is an arithmetic number, because the mean of its divisors is an integer number (6806673408).

Almost surely, 2^20420020221 is an apocalyptic number.

It is an amenable number.

20420020221 is a deficient number, since it is larger than the sum of its proper divisors (6806673411).

20420020221 is an equidigital number, since it uses as much as digits as its factorization.

20420020221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6806673410.

The product of its (nonzero) digits is 128, while the sum is 15.

Adding to 20420020221 its reverse (12202002402), we get a palindrome (32622022623).

The spelling of 20420020221 in words is "twenty billion, four hundred twenty million, twenty thousand, two hundred twenty-one".