215321189 has 2 divisors, whose sum is σ = 215321190. Its totient is φ = 215321188.

The previous prime is 215321179. The next prime is 215321213. The reversal of 215321189 is 981123512.

It is a happy number.

215321189 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169650625 + 45670564 = 13025^2 + 6758^2 .

It is a cyclic number.

It is not a de Polignac number, because 215321189 - 2⁸ = 215320933 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215321179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107660594 + 107660595.

It is an arithmetic number, because the mean of its divisors is an integer number (107660595).

Almost surely, 2^215321189 is an apocalyptic number.

It is an amenable number.

215321189 is a deficient number, since it is larger than the sum of its proper divisors (1).

215321189 is an equidigital number, since it uses as much as digits as its factorization.

215321189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 32.

The square root of 215321189 is about 14673.8266651886. The cubic root of 215321189 is about 599.3708117305.

The spelling of 215321189 in words is "two hundred fifteen million, three hundred twenty-one thousand, one hundred eighty-nine".