210020221021 has 4 divisors (see below), whose sum is σ = 226175622652. Its totient is φ = 193864819392.

The previous prime is 210020221003. The next prime is 210020221039. The reversal of 210020221021 is 120122020012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (210020221003) and next prime (210020221039).

It can be written as a sum of positive squares in 2 ways, for example, as 11094408900 + 198925812121 = 105330^2 + 446011^2 .

It is a cyclic number.

It is not a de Polignac number, because 210020221021 - 2²³ = 210011832413 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 16155401617 = 210020221021 / (2 + 1 + 0 + 0 + 2 + 0 + 2 + 2 + 1 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210020220992 and 210020221010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210020221421) 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, 8077700796 + ... + 8077700821.

It is an arithmetic number, because the mean of its divisors is an integer number (56543905663).

Almost surely, 2^210020221021 is an apocalyptic number.

It is an amenable number.

210020221021 is a deficient number, since it is larger than the sum of its proper divisors (16155401631).

210020221021 is a wasteful number, since it uses less digits than its factorization.

210020221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16155401630.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 210020221021 its reverse (120122020012), we get a palindrome (330142241033).

The spelling of 210020221021 in words is "two hundred ten billion, twenty million, two hundred twenty-one thousand, twenty-one".