1097581 has 4 divisors (see below), whose sum is σ = 1099872. Its totient is φ = 1095292.

The previous prime is 1097557. The next prime is 1097599. The reversal of 1097581 is 1857901.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1857901 = 43 ⋅43207.

It is a cyclic number.

It is not a de Polignac number, because 1097581 - 2⁵ = 1097549 is a prime.

It is a super-2 number, since 2×1097581² = 2409368103122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1097501) 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 3 ways as a sum of consecutive naturals, for example, 121 + ... + 1486.

It is an arithmetic number, because the mean of its divisors is an integer number (274968).

2^1097581 is an apocalyptic number.

It is an amenable number.

1097581 is a deficient number, since it is larger than the sum of its proper divisors (2291).

1097581 is an equidigital number, since it uses as much as digits as its factorization.

1097581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 1097581 is about 1047.6550004653. The cubic root of 1097581 is about 103.1522867493.

The spelling of 1097581 in words is "one million, ninety-seven thousand, five hundred eighty-one".