4056561 has 20 divisors (see below), whose sum is σ = 6166644. Its totient is φ = 2656800.

The previous prime is 4056553. The next prime is 4056583. The reversal of 4056561 is 1656504.

It is a happy number.

4056561 is a `hidden beast` number, since 4 + 0 + 5 + 656 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 518400 + 3538161 = 720^2 + 1881^2 .

It is not a de Polignac number, because 4056561 - 2³ = 4056553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (4056161) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4531 + ... + 5351.

Almost surely, 2^4056561 is an apocalyptic number.

It is an amenable number.

4056561 is a deficient number, since it is larger than the sum of its proper divisors (2110083).

4056561 is an equidigital number, since it uses as much as digits as its factorization.

4056561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 885 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 4056561 is about 2014.0906136517. The cubic root of 4056561 is about 159.4848142826.

The spelling of 4056561 in words is "four million, fifty-six thousand, five hundred sixty-one".