189999368821 has 8 divisors (see below), whose sum is σ = 190405439640. Its totient is φ = 189593722368.

The previous prime is 189999368813. The next prime is 189999368873. The reversal of 189999368821 is 128863999981.

189999368821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 204089796 + 189795279025 = 14286^2 + 435655^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 189999368821 - 2³ = 189999368813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189999362821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 798525 + ... + 1008781.

It is an arithmetic number, because the mean of its divisors is an integer number (23800679955).

Almost surely, 2^189999368821 is an apocalyptic number.

It is an amenable number.

189999368821 is a deficient number, since it is larger than the sum of its proper divisors (406070819).

189999368821 is a wasteful number, since it uses less digits than its factorization.

189999368821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212183.

The product of its digits is 120932352, while the sum is 73.

The spelling of 189999368821 in words is "one hundred eighty-nine billion, nine hundred ninety-nine million, three hundred sixty-eight thousand, eight hundred twenty-one".