189435469021 has 2 divisors, whose sum is σ = 189435469022. Its totient is φ = 189435469020.

The previous prime is 189435469019. The next prime is 189435469031. The reversal of 189435469021 is 120964534981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189394688025 + 40780996 = 435195^2 + 6386^2 .

It is a cyclic number.

It is not a de Polignac number, because 189435469021 - 2¹ = 189435469019 is a prime.

Together with 189435469019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 189435469021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (189435469001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94717734510 + 94717734511.

It is an arithmetic number, because the mean of its divisors is an integer number (94717734511).

Almost surely, 2^189435469021 is an apocalyptic number.

It is an amenable number.

189435469021 is a deficient number, since it is larger than the sum of its proper divisors (1).

189435469021 is an equidigital number, since it uses as much as digits as its factorization.

189435469021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1866240, while the sum is 52.

The spelling of 189435469021 in words is "one hundred eighty-nine billion, four hundred thirty-five million, four hundred sixty-nine thousand, twenty-one".