4016561 has 2 divisors, whose sum is σ = 4016562. Its totient is φ = 4016560.

The previous prime is 4016549. The next prime is 4016563. The reversal of 4016561 is 1656104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3400336 + 616225 = 1844^2 + 785^2 .

It is a cyclic number.

It is not a de Polignac number, because 4016561 - 2¹⁰ = 4015537 is a prime.

It is a super-2 number, since 2×4016561² = 32265524533442, which contains 22 as substring.

Together with 4016563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (4016563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2008280 + 2008281.

It is an arithmetic number, because the mean of its divisors is an integer number (2008281).

Almost surely, 2^4016561 is an apocalyptic number.

It is an amenable number.

4016561 is a deficient number, since it is larger than the sum of its proper divisors (1).

4016561 is an equidigital number, since it uses as much as digits as its factorization.

4016561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 4016561 is about 2004.1359734309. The cubic root of 4016561 is about 158.9588781227.

The spelling of 4016561 in words is "four million, sixteen thousand, five hundred sixty-one".