220021001021 has 4 divisors (see below), whose sum is σ = 221236586844. Its totient is φ = 218805415200.

The previous prime is 220021000999. The next prime is 220021001027. The reversal of 220021001021 is 120100120022.

It is a happy number.

220021001021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 14552803225 + 205468197796 = 120635^2 + 453286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220021001021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220021000993 and 220021001011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220021001027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 607792640 + ... + 607793001.

It is an arithmetic number, because the mean of its divisors is an integer number (55309146711).

Almost surely, 2^220021001021 is an apocalyptic number.

It is an amenable number.

220021001021 is a deficient number, since it is larger than the sum of its proper divisors (1215585823).

220021001021 is a wasteful number, since it uses less digits than its factorization.

220021001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215585822.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 220021001021 its reverse (120100120022), we get a palindrome (340121121043).

The spelling of 220021001021 in words is "two hundred twenty billion, twenty-one million, one thousand, twenty-one".