22041581 has 4 divisors (see below), whose sum is σ = 22050972. Its totient is φ = 22032192.

The previous prime is 22041541. The next prime is 22041583. The reversal of 22041581 is 18514022.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18514022 = 2 ⋅9257011.

It can be written as a sum of positive squares in 2 ways, for example, as 3258025 + 18783556 = 1805^2 + 4334^2 .

It is a cyclic number.

It is not a de Polignac number, because 22041581 - 2⁶ = 22041517 is a prime.

It is a super-2 number, since 2×22041581² = 971662585959122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22041583) 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, 2291 + ... + 7023.

It is an arithmetic number, because the mean of its divisors is an integer number (5512743).

Almost surely, 2^22041581 is an apocalyptic number.

It is an amenable number.

22041581 is a deficient number, since it is larger than the sum of its proper divisors (9391).

22041581 is an equidigital number, since it uses as much as digits as its factorization.

22041581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9390.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 22041581 is about 4694.8462168638. The cubic root of 22041581 is about 280.3803546872.

It can be divided in two parts, 22041 and 581, that added together give a palindrome (22622).

The spelling of 22041581 in words is "twenty-two million, forty-one thousand, five hundred eighty-one".