20011221023 has 2 divisors, whose sum is σ = 20011221024. Its totient is φ = 20011221022.

The previous prime is 20011221017. The next prime is 20011221037. The reversal of 20011221023 is 32012211002.

It is a happy number.

It is an a-pointer prime, because the next prime (20011221037) can be obtained adding 20011221023 to its sum of digits (14).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20011221023 - 2²⁰ = 20010172447 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20011220989 and 20011221007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011221623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005610511 + 10005610512.

It is an arithmetic number, because the mean of its divisors is an integer number (10005610512).

Almost surely, 2^20011221023 is an apocalyptic number.

20011221023 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011221023 is an equidigital number, since it uses as much as digits as its factorization.

20011221023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 20011221023 its reverse (32012211002), we get a palindrome (52023432025).

The spelling of 20011221023 in words is "twenty billion, eleven million, two hundred twenty-one thousand, twenty-three".