1163991 has 8 divisors (see below), whose sum is σ = 1575424. Its totient is φ = 764280.

The previous prime is 1163989. The next prime is 1163993. The reversal of 1163991 is 1993611.

It is an interprime number because it is at equal distance from previous prime (1163989) and next prime (1163993).

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

It is not a de Polignac number, because 1163991 - 2¹ = 1163989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1163993) 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 7 ways as a sum of consecutive naturals, for example, 2695 + ... + 3096.

It is an arithmetic number, because the mean of its divisors is an integer number (196928).

2^1163991 is an apocalyptic number.

1163991 is a deficient number, since it is larger than the sum of its proper divisors (411433).

1163991 is an equidigital number, since it uses as much as digits as its factorization.

1163991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5861.

The product of its digits is 1458, while the sum is 30.

The square root of 1163991 is about 1078.8841457728. The cubic root of 1163991 is about 105.1921199165.

The spelling of 1163991 in words is "one million, one hundred sixty-three thousand, nine hundred ninety-one".