210021122221021 has 4 divisors (see below), whose sum is σ = 210088674852700. Its totient is φ = 209953569589344.

The previous prime is 210021122220971. The next prime is 210021122221063. The reversal of 210021122221021 is 120122221120012.

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 136267567156900 + 73753555064121 = 11673370^2 + 8587989^2 .

It is a cyclic number.

It is not a de Polignac number, because 210021122221021 - 2¹³ = 210021122212829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 210021122221021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210021122221621) 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, 33776311176 + ... + 33776317393.

It is an arithmetic number, because the mean of its divisors is an integer number (52522168713175).

Almost surely, 2^{210021122221021} is an apocalyptic number.

It is an amenable number.

210021122221021 is a deficient number, since it is larger than the sum of its proper divisors (67552631679).

210021122221021 is an equidigital number, since it uses as much as digits as its factorization.

210021122221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67552631678.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 210021122221021 its reverse (120122221120012), we get a palindrome (330143343341033).

The spelling of 210021122221021 in words is "two hundred ten trillion, twenty-one billion, one hundred twenty-two million, two hundred twenty-one thousand, twenty-one".