191589989 has 4 divisors (see below), whose sum is σ = 193052640. Its totient is φ = 190127340.

The previous prime is 191589973. The next prime is 191590073. The reversal of 191589989 is 989985191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 191589989 - 2⁴ = 191589973 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 (191589919) 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 in 3 ways as a sum of consecutive naturals, for example, 731129 + ... + 731390.

It is an arithmetic number, because the mean of its divisors is an integer number (48263160).

Almost surely, 2^191589989 is an apocalyptic number.

It is an amenable number.

191589989 is a deficient number, since it is larger than the sum of its proper divisors (1462651).

191589989 is a wasteful number, since it uses less digits than its factorization.

191589989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1462650.

The product of its digits is 2099520, while the sum is 59.

The square root of 191589989 is about 13841.6035559468. The cubic root of 191589989 is about 576.4888839440.

The spelling of 191589989 in words is "one hundred ninety-one million, five hundred eighty-nine thousand, nine hundred eighty-nine".