1155891 has 8 divisors (see below), whose sum is σ = 1681344. Its totient is φ = 700520.

The previous prime is 1155863. The next prime is 1155899. The reversal of 1155891 is 1985511.

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

It is a cyclic number.

It is not a de Polignac number, because 1155891 - 2⁵ = 1155859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1155899) 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, 17481 + ... + 17546.

It is an arithmetic number, because the mean of its divisors is an integer number (210168).

2^1155891 is an apocalyptic number.

1155891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1155891 is a deficient number, since it is larger than the sum of its proper divisors (525453).

1155891 is a wasteful number, since it uses less digits than its factorization.

1155891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35041.

The product of its digits is 1800, while the sum is 30.

The square root of 1155891 is about 1075.1237138116. The cubic root of 1155891 is about 104.9475474980.

It can be divided in two parts, 115 and 5891, that added together give a palindrome (6006).

The spelling of 1155891 in words is "one million, one hundred fifty-five thousand, eight hundred ninety-one".