1191381565 has 8 divisors (see below), whose sum is σ = 1559626848. Its totient is φ = 866459280.

The previous prime is 1191381551. The next prime is 1191381571. The reversal of 1191381565 is 5651831911.

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

It is not a de Polignac number, because 1191381565 - 2¹³ = 1191373373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 10830687 + ... + 10830796.

It is an arithmetic number, because the mean of its divisors is an integer number (194953356).

Almost surely, 2^1191381565 is an apocalyptic number.

It is an amenable number.

1191381565 is a deficient number, since it is larger than the sum of its proper divisors (368245283).

1191381565 is a wasteful number, since it uses less digits than its factorization.

1191381565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21661499.

The product of its digits is 32400, while the sum is 40.

The square root of 1191381565 is about 34516.3955968754. The cubic root of 1191381565 is about 1060.1084394223.

The spelling of 1191381565 in words is "one billion, one hundred ninety-one million, three hundred eighty-one thousand, five hundred sixty-five".