1191885155 has 4 divisors (see below), whose sum is σ = 1430262192. Its totient is φ = 953508120.

The previous prime is 1191885151. The next prime is 1191885157. The reversal of 1191885155 is 5515881911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5515881911 = 167 ⋅33029233.

It is not a de Polignac number, because 1191885155 - 2² = 1191885151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1191885151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119188511 + ... + 119188520.

It is an arithmetic number, because the mean of its divisors is an integer number (357565548).

Almost surely, 2^1191885155 is an apocalyptic number.

1191885155 is a deficient number, since it is larger than the sum of its proper divisors (238377037).

1191885155 is an equidigital number, since it uses as much as digits as its factorization.

1191885155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238377036.

The product of its digits is 72000, while the sum is 44.

The square root of 1191885155 is about 34523.6897651453. The cubic root of 1191885155 is about 1060.2577855883.

The spelling of 1191885155 in words is "one billion, one hundred ninety-one million, eight hundred eighty-five thousand, one hundred fifty-five".