1091831 has 4 divisors (see below), whose sum is σ = 1175832. Its totient is φ = 1007832.

The previous prime is 1091809. The next prime is 1091837. The reversal of 1091831 is 1381901.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1091831 - 2¹⁰ = 1090807 is a prime.

It is a super-2 number, since 2×1091831² = 2384189865122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1091797 and 1091806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091837) 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 3 ways as a sum of consecutive naturals, for example, 41981 + ... + 42006.

It is an arithmetic number, because the mean of its divisors is an integer number (293958).

2^1091831 is an apocalyptic number.

1091831 is a deficient number, since it is larger than the sum of its proper divisors (84001).

1091831 is an equidigital number, since it uses as much as digits as its factorization.

1091831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84000.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 1091831 is about 1044.9071729106. The cubic root of 1091831 is about 102.9718401040.

The spelling of 1091831 in words is "one million, ninety-one thousand, eight hundred thirty-one".