21020211220189 has 2 divisors, whose sum is σ = 21020211220190. Its totient is φ = 21020211220188.

The previous prime is 21020211220139. The next prime is 21020211220219. The reversal of 21020211220189 is 98102211202012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15120937759225 + 5899273460964 = 3888565^2 + 2428842^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020211220189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21020211220189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020211220109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510105610094 + 10510105610095.

It is an arithmetic number, because the mean of its divisors is an integer number (10510105610095).

Almost surely, 2^{21020211220189} is an apocalyptic number.

It is an amenable number.

21020211220189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020211220189 is an equidigital number, since it uses as much as digits as its factorization.

21020211220189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The spelling of 21020211220189 in words is "twenty-one trillion, twenty billion, two hundred eleven million, two hundred twenty thousand, one hundred eighty-nine".