1161891 has 16 divisors (see below), whose sum is σ = 1797120. Its totient is φ = 740520.

The previous prime is 1161883. The next prime is 1161893. The reversal of 1161891 is 1981611.

It is not a de Polignac number, because 1161891 - 2³ = 1161883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1161893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315 + ... + 1556.

It is an arithmetic number, because the mean of its divisors is an integer number (112320).

2^1161891 is an apocalyptic number.

1161891 is a deficient number, since it is larger than the sum of its proper divisors (635229).

1161891 is a wasteful number, since it uses less digits than its factorization.

1161891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1903 (or 1897 counting only the distinct ones).

The product of its digits is 432, while the sum is 27.

The square root of 1161891 is about 1077.9104786577. The cubic root of 1161891 is about 105.1288214798.

The spelling of 1161891 in words is "one million, one hundred sixty-one thousand, eight hundred ninety-one".