1091531 has 16 divisors (see below), whose sum is σ = 1363200. Its totient is φ = 852768.

The previous prime is 1091527. The next prime is 1091549. The reversal of 1091531 is 1351901.

It is not a de Polignac number, because 1091531 - 2² = 1091527 is a prime.

It is a super-2 number, since 2×1091531² = 2382879847922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1091521) 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, 3716 + ... + 3998.

It is an arithmetic number, because the mean of its divisors is an integer number (85200).

2^1091531 is an apocalyptic number.

1091531 is a deficient number, since it is larger than the sum of its proper divisors (271669).

1091531 is a wasteful number, since it uses less digits than its factorization.

1091531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338.

The product of its (nonzero) digits is 135, while the sum is 20.

The square root of 1091531 is about 1044.7636096266. The cubic root of 1091531 is about 102.9624081249.

The spelling of 1091531 in words is "one million, ninety-one thousand, five hundred thirty-one".