5661509 has 12 divisors (see below), whose sum is σ = 6741504. Its totient is φ = 4738104.

The previous prime is 5661503. The next prime is 5661517. The reversal of 5661509 is 9051665.

It is a de Polignac number, because none of the positive numbers 2^k-5661509 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 764 + ... + 3450.

It is an arithmetic number, because the mean of its divisors is an integer number (561792).

Almost surely, 2^5661509 is an apocalyptic number.

It is an amenable number.

5661509 is a deficient number, since it is larger than the sum of its proper divisors (1079995).

5661509 is a wasteful number, since it uses less digits than its factorization.

5661509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2744 (or 2737 counting only the distinct ones).

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 5661509 is about 2379.3925695437. The cubic root of 5661509 is about 178.2286020473.

The spelling of 5661509 in words is "five million, six hundred sixty-one thousand, five hundred nine".