210202220021 has 4 divisors (see below), whose sum is σ = 210328166700. Its totient is φ = 210076273344.

The previous prime is 210202219967. The next prime is 210202220023. The reversal of 210202220021 is 120022202012.

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 153456310225 + 56745909796 = 391735^2 + 238214^2 .

It is a cyclic number.

It is not a de Polignac number, because 210202220021 - 2¹⁸ = 210201957877 is a prime.

It is a super-3 number, since 3×210202220021³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210202219978 and 210202220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210202220023) 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, 62970836 + ... + 62974173.

It is an arithmetic number, because the mean of its divisors is an integer number (52582041675).

Almost surely, 2^210202220021 is an apocalyptic number.

It is an amenable number.

210202220021 is a deficient number, since it is larger than the sum of its proper divisors (125946679).

210202220021 is a wasteful number, since it uses less digits than its factorization.

210202220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125946678.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 210202220021 its reverse (120022202012), we get a palindrome (330224422033).

The spelling of 210202220021 in words is "two hundred ten billion, two hundred two million, two hundred twenty thousand, twenty-one".