4099561 has 2 divisors, whose sum is σ = 4099562. Its totient is φ = 4099560.

The previous prime is 4099541. The next prime is 4099591. The reversal of 4099561 is 1659904.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2742336 + 1357225 = 1656^2 + 1165^2 .

It is a cyclic number.

It is not a de Polignac number, because 4099561 - 2⁹ = 4099049 is a prime.

4099561 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (4099531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2049780 + 2049781.

It is an arithmetic number, because the mean of its divisors is an integer number (2049781).

Almost surely, 2^4099561 is an apocalyptic number.

It is an amenable number.

4099561 is a deficient number, since it is larger than the sum of its proper divisors (1).

4099561 is an equidigital number, since it uses as much as digits as its factorization.

4099561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 4099561 is about 2024.7372669065. The cubic root of 4099561 is about 160.0463537570.

The spelling of 4099561 in words is "four million, ninety-nine thousand, five hundred sixty-one".