189878830861 has 2 divisors, whose sum is σ = 189878830862. Its totient is φ = 189878830860.

The previous prime is 189878830837. The next prime is 189878830873. The reversal of 189878830861 is 168038878981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99473375236 + 90405455625 = 315394^2 + 300675^2 .

It is a cyclic number.

It is not a de Polignac number, because 189878830861 - 2¹⁵ = 189878798093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189878830261) 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, 94939415430 + 94939415431.

It is an arithmetic number, because the mean of its divisors is an integer number (94939415431).

Almost surely, 2^189878830861 is an apocalyptic number.

It is an amenable number.

189878830861 is a deficient number, since it is larger than the sum of its proper divisors (1).

189878830861 is an equidigital number, since it uses as much as digits as its factorization.

189878830861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37158912, while the sum is 67.

The spelling of 189878830861 in words is "one hundred eighty-nine billion, eight hundred seventy-eight million, eight hundred thirty thousand, eight hundred sixty-one".