21220121002189 has 2 divisors, whose sum is σ = 21220121002190. Its totient is φ = 21220121002188.

The previous prime is 21220121002141. The next prime is 21220121002217. The reversal of 21220121002189 is 98120012102212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17870276655625 + 3349844346564 = 4227325^2 + 1830258^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220121002189 - 2³¹ = 21217973518541 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21220121002189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220121002489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610060501094 + 10610060501095.

It is an arithmetic number, because the mean of its divisors is an integer number (10610060501095).

Almost surely, 2^{21220121002189} is an apocalyptic number.

It is an amenable number.

21220121002189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220121002189 is an equidigital number, since it uses as much as digits as its factorization.

21220121002189 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21220121002189 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two thousand, one hundred eighty-nine".