1191688389 has 32 divisors (see below), whose sum is σ = 1886544000. Its totient is φ = 740835072.

The previous prime is 1191688361. The next prime is 1191688403. The reversal of 1191688389 is 9838861911.

It is not a de Polignac number, because 1191688389 - 2¹² = 1191684293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191688319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38122 + ... + 61940.

It is an arithmetic number, because the mean of its divisors is an integer number (58954500).

Almost surely, 2^1191688389 is an apocalyptic number.

It is an amenable number.

1191688389 is a deficient number, since it is larger than the sum of its proper divisors (694855611).

1191688389 is a wasteful number, since it uses less digits than its factorization.

1191688389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23954 (or 23948 counting only the distinct ones).

The product of its digits is 746496, while the sum is 54.

The square root of 1191688389 is about 34520.8399231537. The cubic root of 1191688389 is about 1060.1994370794.

The spelling of 1191688389 in words is "one billion, one hundred ninety-one million, six hundred eighty-eight thousand, three hundred eighty-nine".