1153991 has 8 divisors (see below), whose sum is σ = 1208064. Its totient is φ = 1101240.

The previous prime is 1153973. The next prime is 1154017. The reversal of 1153991 is 1993511.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1153991 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1153921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1736 + ... + 2306.

It is an arithmetic number, because the mean of its divisors is an integer number (151008).

2^1153991 is an apocalyptic number.

1153991 is a deficient number, since it is larger than the sum of its proper divisors (54073).

1153991 is an equidigital number, since it uses as much as digits as its factorization.

1153991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661.

The product of its digits is 1215, while the sum is 29.

The square root of 1153991 is about 1074.2397311587. The cubic root of 1153991 is about 104.8900133259.

The spelling of 1153991 in words is "one million, one hundred fifty-three thousand, nine hundred ninety-one".