3209561 has 2 divisors, whose sum is σ = 3209562. Its totient is φ = 3209560.

The previous prime is 3209543. The next prime is 3209579. The reversal of 3209561 is 1659023.

It is a balanced prime because it is at equal distance from previous prime (3209543) and next prime (3209579).

It can be written as a sum of positive squares in only one way, i.e., 3083536 + 126025 = 1756^2 + 355^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3209561 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3209561.

It is not a weakly prime, because it can be changed into another prime (3209161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1604780 + 1604781.

It is an arithmetic number, because the mean of its divisors is an integer number (1604781).

Almost surely, 2^3209561 is an apocalyptic number.

It is an amenable number.

3209561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3209561 is an equidigital number, since it uses as much as digits as its factorization.

3209561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 3209561 is about 1791.5247695748. The cubic root of 3209561 is about 147.5078766262.

The spelling of 3209561 in words is "three million, two hundred nine thousand, five hundred sixty-one".