2121212189 has 2 divisors, whose sum is σ = 2121212190. Its totient is φ = 2121212188.

The previous prime is 2121212147. The next prime is 2121212207. The reversal of 2121212189 is 9812121212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1665048025 + 456164164 = 40805^2 + 21358^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121212189 - 2¹² = 2121208093 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121212089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060606094 + 1060606095.

It is an arithmetic number, because the mean of its divisors is an integer number (1060606095).

Almost surely, 2^2121212189 is an apocalyptic number.

It is an amenable number.

2121212189 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121212189 is an equidigital number, since it uses as much as digits as its factorization.

2121212189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 29.

The square root of 2121212189 is about 46056.6193831028. The cubic root of 2121212189 is about 1284.8764564011.

The spelling of 2121212189 in words is "two billion, one hundred twenty-one million, two hundred twelve thousand, one hundred eighty-nine".