1001331 has 24 divisors (see below), whose sum is σ = 1549184. Its totient is φ = 622080.

The previous prime is 1001327. The next prime is 1001347. The reversal of 1001331 is 1331001.

It is not a de Polignac number, because 1001331 - 2² = 1001327 is a prime.

It is a super-2 number, since 2×1001331² = 2005327543122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

1001331 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1001311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10275 + ... + 10371.

2^1001331 is an apocalyptic number.

1001331 is a deficient number, since it is larger than the sum of its proper divisors (547853).

1001331 is a wasteful number, since it uses less digits than its factorization.

1001331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 9.

The square root of 1001331 is about 1000.6652787021. The cubic root of 1001331 is about 100.0443469972.

Adding to 1001331 its reverse (1331001), we get a palindrome (2332332).

It can be divided in two parts, 100 and 1331, that added together give a triangular number (1431 = T₅₃).

The spelling of 1001331 in words is "one million, one thousand, three hundred thirty-one".