20020021121 has 2 divisors, whose sum is σ = 20020021122. Its totient is φ = 20020021120.

The previous prime is 20020021067. The next prime is 20020021127. The reversal of 20020021121 is 12112002002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15052590721 + 4967430400 = 122689^2 + 70480^2 .

It is a cyclic number.

It is not a de Polignac number, because 20020021121 - 2⁶ = 20020021057 is a prime.

It is not a weakly prime, because it can be changed into another prime (20020021127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010010560 + 10010010561.

It is an arithmetic number, because the mean of its divisors is an integer number (10010010561).

Almost surely, 2^20020021121 is an apocalyptic number.

It is an amenable number.

20020021121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20020021121 is an equidigital number, since it uses as much as digits as its factorization.

20020021121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20020021121 its reverse (12112002002), we get a palindrome (32132023123).

The spelling of 20020021121 in words is "twenty billion, twenty million, twenty-one thousand, one hundred twenty-one".