21121012189 has 2 divisors, whose sum is σ = 21121012190. Its totient is φ = 21121012188.

The previous prime is 21121012103. The next prime is 21121012207. The reversal of 21121012189 is 98121012112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19197488025 + 1923524164 = 138555^2 + 43858^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121012189 - 2¹³ = 21121003997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121012489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560506094 + 10560506095.

It is an arithmetic number, because the mean of its divisors is an integer number (10560506095).

Almost surely, 2^21121012189 is an apocalyptic number.

It is an amenable number.

21121012189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121012189 is an equidigital number, since it uses as much as digits as its factorization.

21121012189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 21121012189 in words is "twenty-one billion, one hundred twenty-one million, twelve thousand, one hundred eighty-nine".