2132561 has 4 divisors (see below), whose sum is σ = 2172852. Its totient is φ = 2092272.

The previous prime is 2132551. The next prime is 2132563. The reversal of 2132561 is 1652312.

2132561 = 86² + 87² + ... + 191².

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 1577536 + 555025 = 1256^2 + 745^2 .

It is a cyclic number.

It is not a de Polignac number, because 2132561 - 2¹⁰ = 2131537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2132563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20066 + ... + 20171.

It is an arithmetic number, because the mean of its divisors is an integer number (543213).

2^2132561 is an apocalyptic number.

It is an amenable number.

2132561 is a deficient number, since it is larger than the sum of its proper divisors (40291).

2132561 is an equidigital number, since it uses as much as digits as its factorization.

2132561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40290.

The product of its digits is 360, while the sum is 20.

The square root of 2132561 is about 1460.3290725039. The cubic root of 2132561 is about 128.7163810799.

Adding to 2132561 its reverse (1652312), we get a palindrome (3784873).

Subtracting from 2132561 its reverse (1652312), we obtain a square (480249 = 693²).

The spelling of 2132561 in words is "two million, one hundred thirty-two thousand, five hundred sixty-one".