55616509 has 4 divisors (see below), whose sum is σ = 59894716. Its totient is φ = 51338304.

The previous prime is 55616479. The next prime is 55616549. The reversal of 55616509 is 90561655.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22231225 + 33385284 = 4715^2 + 5778^2 .

It is a cyclic number.

It is not a de Polignac number, because 55616509 - 2²¹ = 53519357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55616549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2139084 + ... + 2139109.

It is an arithmetic number, because the mean of its divisors is an integer number (14973679).

Almost surely, 2^55616509 is an apocalyptic number.

It is an amenable number.

55616509 is a deficient number, since it is larger than the sum of its proper divisors (4278207).

55616509 is a wasteful number, since it uses less digits than its factorization.

55616509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4278206.

The product of its (nonzero) digits is 40500, while the sum is 37.

The square root of 55616509 is about 7457.6476854300. The cubic root of 55616509 is about 381.7109117317.

The spelling of 55616509 in words is "fifty-five million, six hundred sixteen thousand, five hundred nine".