1191885387 has 16 divisors (see below), whose sum is σ = 1981316352. Its totient is φ = 619161120.

The previous prime is 1191885379. The next prime is 1191885389. The reversal of 1191885387 is 7835881911.

It is not a de Polignac number, because 1191885387 - 2³ = 1191885379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1191885389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2579608 + ... + 2580069.

It is an arithmetic number, because the mean of its divisors is an integer number (123832272).

Almost surely, 2^1191885387 is an apocalyptic number.

1191885387 is a deficient number, since it is larger than the sum of its proper divisors (789430965).

1191885387 is a wasteful number, since it uses less digits than its factorization.

1191885387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5159698.

The product of its digits is 483840, while the sum is 51.

The square root of 1191885387 is about 34523.6931251568. The cubic root of 1191885387 is about 1060.2578543812.

The spelling of 1191885387 in words is "one billion, one hundred ninety-one million, eight hundred eighty-five thousand, three hundred eighty-seven".