21210220189 has 2 divisors, whose sum is σ = 21210220190. Its totient is φ = 21210220188.

The previous prime is 21210220183. The next prime is 21210220211. The reversal of 21210220189 is 98102201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19778203225 + 1432016964 = 140635^2 + 37842^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210220189 - 2¹⁵ = 21210187421 is a prime.

It is a super-4 number, since 4×21210220189⁴ (a number of 42 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210220183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605110094 + 10605110095.

It is an arithmetic number, because the mean of its divisors is an integer number (10605110095).

Almost surely, 2^21210220189 is an apocalyptic number.

It is an amenable number.

21210220189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210220189 is an equidigital number, since it uses as much as digits as its factorization.

21210220189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

The spelling of 21210220189 in words is "twenty-one billion, two hundred ten million, two hundred twenty thousand, one hundred eighty-nine".