2021021220161 has 2 divisors, whose sum is σ = 2021021220162. Its totient is φ = 2021021220160.

The previous prime is 2021021220107. The next prime is 2021021220181. The reversal of 2021021220161 is 1610221201202.

It is an a-pointer prime, because the next prime (2021021220181) can be obtained adding 2021021220161 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1839007210000 + 182014010161 = 1356100^2 + 426631^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021021220161 - 2²² = 2021017025857 is a prime.

It is not a weakly prime, because it can be changed into another prime (2021021220181) 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 as a sum of consecutive naturals, namely, 1010510610080 + 1010510610081.

It is an arithmetic number, because the mean of its divisors is an integer number (1010510610081).

Almost surely, 2^{2021021220161} is an apocalyptic number.

It is an amenable number.

2021021220161 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021021220161 is an equidigital number, since it uses as much as digits as its factorization.

2021021220161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 2021021220161 its reverse (1610221201202), we get a palindrome (3631242421363).

The spelling of 2021021220161 in words is "two trillion, twenty-one billion, twenty-one million, two hundred twenty thousand, one hundred sixty-one".