2106561 has 8 divisors (see below), whose sum is σ = 2847520. Its totient is φ = 1384992.

The previous prime is 2106551. The next prime is 2106563. The reversal of 2106561 is 1656012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2106561 - 2⁵ = 2106529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2106563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4591 + ... + 5028.

It is an arithmetic number, because the mean of its divisors is an integer number (355940).

2^2106561 is an apocalyptic number.

It is an amenable number.

2106561 is a deficient number, since it is larger than the sum of its proper divisors (740959).

2106561 is an equidigital number, since it uses as much as digits as its factorization.

2106561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9695.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 2106561 is about 1451.3996692848. The cubic root of 2106561 is about 128.1911410241.

The spelling of 2106561 in words is "two million, one hundred six thousand, five hundred sixty-one".