189215430821 has 2 divisors, whose sum is σ = 189215430822. Its totient is φ = 189215430820.

The previous prime is 189215430799. The next prime is 189215430893. The reversal of 189215430821 is 128034512981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185532640225 + 3682790596 = 430735^2 + 60686^2 .

It is an emirp because it is prime and its reverse (128034512981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 189215430821 - 2²² = 189211236517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189215432821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94607715410 + 94607715411.

It is an arithmetic number, because the mean of its divisors is an integer number (94607715411).

Almost surely, 2^189215430821 is an apocalyptic number.

It is an amenable number.

189215430821 is a deficient number, since it is larger than the sum of its proper divisors (1).

189215430821 is an equidigital number, since it uses as much as digits as its factorization.

189215430821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 189215430821 in words is "one hundred eighty-nine billion, two hundred fifteen million, four hundred thirty thousand, eight hundred twenty-one".