1841581 has 4 divisors (see below), whose sum is σ = 2104672. Its totient is φ = 1578492.

The previous prime is 1841579. The next prime is 1841599. The reversal of 1841581 is 1851481.

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: 1851481 = 83 ⋅22307.

It is a cyclic number.

It is not a de Polignac number, because 1841581 - 2¹ = 1841579 is a prime.

It is a super-2 number, since 2×1841581² = 6782841159122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1841531) 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, 131535 + ... + 131548.

It is an arithmetic number, because the mean of its divisors is an integer number (526168).

2^1841581 is an apocalyptic number.

It is an amenable number.

1841581 is a deficient number, since it is larger than the sum of its proper divisors (263091).

1841581 is an equidigital number, since it uses as much as digits as its factorization.

1841581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263090.

The product of its digits is 1280, while the sum is 28.

The square root of 1841581 is about 1357.0486358270. The cubic root of 1841581 is about 122.5736000858.

It can be divided in two parts, 18415 and 81, that added together give a square (18496 = 136²).

The spelling of 1841581 in words is "one million, eight hundred forty-one thousand, five hundred eighty-one".