20220121 has 2 divisors, whose sum is σ = 20220122. Its totient is φ = 20220120.

The previous prime is 20220119. The next prime is 20220127. The reversal of 20220121 is 12102202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 4260096 = 3995^2 + 2064^2 .

It is a cyclic number.

It is not a de Polignac number, because 20220121 - 2¹ = 20220119 is a prime.

Together with 20220119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 20220098 and 20220107.

It is not a weakly prime, because it can be changed into another prime (20220127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110060 + 10110061.

It is an arithmetic number, because the mean of its divisors is an integer number (10110061).

Almost surely, 2^20220121 is an apocalyptic number.

It is an amenable number.

20220121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20220121 is an equidigital number, since it uses as much as digits as its factorization.

20220121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 20220121 is about 4496.6788855777. The cubic root of 20220121 is about 272.4339643034.

Adding to 20220121 its reverse (12102202), we get a palindrome (32322323).

The spelling of 20220121 in words is "twenty million, two hundred twenty thousand, one hundred twenty-one".