2126581 has 4 divisors (see below), whose sum is σ = 2251692. Its totient is φ = 2001472.

The previous prime is 2126573. The next prime is 2126587. The reversal of 2126581 is 1856212.

2126581 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 1932100 + 194481 = 1390^2 + 441^2 .

It is a cyclic number.

It is not a de Polignac number, because 2126581 - 2³ = 2126573 is a prime.

It is a super-2 number, since 2×2126581² = 9044693499122, which contains 22 as substring.

It is a Duffinian number.

2126581 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2126587) 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, 62530 + ... + 62563.

It is an arithmetic number, because the mean of its divisors is an integer number (562923).

2^2126581 is an apocalyptic number.

It is an amenable number.

2126581 is a deficient number, since it is larger than the sum of its proper divisors (125111).

2126581 is a wasteful number, since it uses less digits than its factorization.

2126581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125110.

The product of its digits is 960, while the sum is 25.

The square root of 2126581 is about 1458.2801514112. The cubic root of 2126581 is about 128.5959555207.

The spelling of 2126581 in words is "two million, one hundred twenty-six thousand, five hundred eighty-one".