3616561 has 16 divisors (see below), whose sum is σ = 4127760. Its totient is φ = 3144960.

The previous prime is 3616549. The next prime is 3616573. The reversal of 3616561 is 1656163.

It is an interprime number because it is at equal distance from previous prime (3616549) and next prime (3616573).

It can be written as a sum of positive squares in 8 ways, for example, as 571536 + 3045025 = 756^2 + 1745^2 .

It is not a de Polignac number, because 3616561 - 2⁹ = 3616049 is a prime.

It is an alternating number because its digits alternate between odd and even.

3616561 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3616531) 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 in 15 ways as a sum of consecutive naturals, for example, 19891 + ... + 20071.

It is an arithmetic number, because the mean of its divisors is an integer number (257985).

Almost surely, 2^3616561 is an apocalyptic number.

It is an amenable number.

3616561 is a deficient number, since it is larger than the sum of its proper divisors (511199).

3616561 is a wasteful number, since it uses less digits than its factorization.

3616561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276.

The product of its digits is 3240, while the sum is 28.

The square root of 3616561 is about 1901.7257951661. The cubic root of 3616561 is about 153.4965427679.

It can be divided in two parts, 361 and 6561, that multiplied together give a square (2368521 = 1539²).

The spelling of 3616561 in words is "three million, six hundred sixteen thousand, five hundred sixty-one".