55685609 has 18 divisors (see below), whose sum is σ = 66089790. Its totient is φ = 46776576.

The previous prime is 55685551. The next prime is 55685639. The reversal of 55685609 is 90658655.

It can be written as a sum of positive squares in 3 ways, for example, as 9486400 + 46199209 = 3080^2 + 6797^2 .

It is not a de Polignac number, because 55685609 - 2¹² = 55681513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55685609.

It is not an unprimeable number, because it can be changed into a prime (55685639) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 492737 + ... + 492849.

It is an arithmetic number, because the mean of its divisors is an integer number (3671655).

Almost surely, 2^55685609 is an apocalyptic number.

It is an amenable number.

55685609 is a deficient number, since it is larger than the sum of its proper divisors (10404181).

55685609 is an equidigital number, since it uses as much as digits as its factorization.

55685609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 44.

The square root of 55685609 is about 7462.2790754568. The cubic root of 55685609 is about 381.8689302075.

The spelling of 55685609 in words is "fifty-five million, six hundred eighty-five thousand, six hundred nine".