1191955785 has 16 divisors (see below), whose sum is σ = 2007504960. Its totient is φ = 602251200.

The previous prime is 1191955727. The next prime is 1191955801. The reversal of 1191955785 is 5875591911.

It is not a de Polignac number, because 1191955785 - 2⁸ = 1191955529 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2090866 + ... + 2091435.

It is an arithmetic number, because the mean of its divisors is an integer number (125469060).

Almost surely, 2^1191955785 is an apocalyptic number.

1191955785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1191955785 is a deficient number, since it is larger than the sum of its proper divisors (815549175).

1191955785 is a wasteful number, since it uses less digits than its factorization.

1191955785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4182328.

The product of its digits is 567000, while the sum is 51.

The square root of 1191955785 is about 34524.7126707812. The cubic root of 1191955785 is about 1060.2787284697.

It can be divided in two parts, 1191955 and 785, that added together give a triangular number (1192740 = T₁₅₄₄).

The spelling of 1191955785 in words is "one billion, one hundred ninety-one million, nine hundred fifty-five thousand, seven hundred eighty-five".