2143581 has 16 divisors (see below), whose sum is σ = 3302208. Its totient is φ = 1222400.

The previous prime is 2143579. The next prime is 2143621. The reversal of 2143581 is 1853412.

2143581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 2143581 - 2¹ = 2143579 is a prime.

It is a super-2 number, since 2×2143581² = 9189879007122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2143501) 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 15 ways as a sum of consecutive naturals, for example, 1350 + ... + 2471.

It is an arithmetic number, because the mean of its divisors is an integer number (206388).

2^2143581 is an apocalyptic number.

It is an amenable number.

2143581 is a deficient number, since it is larger than the sum of its proper divisors (1158627).

2143581 is a wasteful number, since it uses less digits than its factorization.

2143581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3852.

The product of its digits is 960, while the sum is 24.

The square root of 2143581 is about 1464.0973328300. The cubic root of 2143581 is about 128.9377140569.

Adding to 2143581 its reverse (1853412), we get a palindrome (3996993).

The spelling of 2143581 in words is "two million, one hundred forty-three thousand, five hundred eighty-one".