20022221221 has 2 divisors, whose sum is σ = 20022221222. Its totient is φ = 20022221220.

The previous prime is 20022221201. The next prime is 20022221237. The reversal of 20022221221 is 12212222002.

It is an a-pointer prime, because the next prime (20022221237) can be obtained adding 20022221221 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18765164196 + 1257057025 = 136986^2 + 35455^2 .

It is a cyclic number.

It is not a de Polignac number, because 20022221221 - 2¹⁵ = 20022188453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20022221195 and 20022221204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20022221201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10011110610 + 10011110611.

It is an arithmetic number, because the mean of its divisors is an integer number (10011110611).

Almost surely, 2^20022221221 is an apocalyptic number.

It is an amenable number.

20022221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

20022221221 is an equidigital number, since it uses as much as digits as its factorization.

20022221221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 20022221221 its reverse (12212222002), we get a palindrome (32234443223).

The spelling of 20022221221 in words is "twenty billion, twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".