4156561 has 2 divisors, whose sum is σ = 4156562. Its totient is φ = 4156560.

The previous prime is 4156549. The next prime is 4156571. The reversal of 4156561 is 1656514.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3825936 + 330625 = 1956^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 4156561 - 2⁷ = 4156433 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (4156531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2078280 + 2078281.

It is an arithmetic number, because the mean of its divisors is an integer number (2078281).

Almost surely, 2^4156561 is an apocalyptic number.

It is an amenable number.

4156561 is a deficient number, since it is larger than the sum of its proper divisors (1).

4156561 is an equidigital number, since it uses as much as digits as its factorization.

4156561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 28.

The square root of 4156561 is about 2038.7645768945. The cubic root of 4156561 is about 160.7846999337.

The spelling of 4156561 in words is "four million, one hundred fifty-six thousand, five hundred sixty-one".