2193581 has 4 divisors (see below), whose sum is σ = 2362332. Its totient is φ = 2024832.

The previous prime is 2193557. The next prime is 2193599. The reversal of 2193581 is 1853912.

2193581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 477481 + 1716100 = 691^2 + 1310^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2193581 is a prime.

It is a super-2 number, since 2×2193581² = 9623595207122, 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 (2193181) 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, 84356 + ... + 84381.

It is an arithmetic number, because the mean of its divisors is an integer number (590583).

2^2193581 is an apocalyptic number.

It is an amenable number.

2193581 is a deficient number, since it is larger than the sum of its proper divisors (168751).

2193581 is a wasteful number, since it uses less digits than its factorization.

2193581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168750.

The product of its digits is 2160, while the sum is 29.

The square root of 2193581 is about 1481.0742722767. The cubic root of 2193581 is about 129.9325290907.

The spelling of 2193581 in words is "two million, one hundred ninety-three thousand, five hundred eighty-one".