5561561 has 4 divisors (see below), whose sum is σ = 5803392. Its totient is φ = 5319732.

The previous prime is 5561537. The next prime is 5561579. The reversal of 5561561 is 1651655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1651655 = 5 ⋅330331.

It is a cyclic number.

It is not a de Polignac number, because 5561561 - 2⁶ = 5561497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5561531) 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 3 ways as a sum of consecutive naturals, for example, 120881 + ... + 120926.

It is an arithmetic number, because the mean of its divisors is an integer number (1450848).

Almost surely, 2^5561561 is an apocalyptic number.

It is an amenable number.

5561561 is a deficient number, since it is larger than the sum of its proper divisors (241831).

5561561 is a wasteful number, since it uses less digits than its factorization.

5561561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241830.

The product of its digits is 4500, while the sum is 29.

The square root of 5561561 is about 2358.2962070105. The cubic root of 5561561 is about 177.1735559191.

It can be divided in two parts, 55 and 61561, that added together give a palindrome (61616).

The spelling of 5561561 in words is "five million, five hundred sixty-one thousand, five hundred sixty-one".