189664391 has 8 divisors (see below), whose sum is σ = 218994720. Its totient is φ = 160892928.

The previous prime is 189664373. The next prime is 189664451. The reversal of 189664391 is 193466981.

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

It is not a de Polignac number, because 189664391 - 2¹⁰ = 189663367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189664351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138986 + ... + 140343.

It is an arithmetic number, because the mean of its divisors is an integer number (27374340).

Almost surely, 2^189664391 is an apocalyptic number.

189664391 is a deficient number, since it is larger than the sum of its proper divisors (29330329).

189664391 is an equidigital number, since it uses as much as digits as its factorization.

189664391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279433.

The product of its digits is 279936, while the sum is 47.

The square root of 189664391 is about 13771.8695535501. The cubic root of 189664391 is about 574.5510204011.

The spelling of 189664391 in words is "one hundred eighty-nine million, six hundred sixty-four thousand, three hundred ninety-one".