55561709 has 16 divisors (see below), whose sum is σ = 66078720. Its totient is φ = 45709440.

The previous prime is 55561699. The next prime is 55561711. The reversal of 55561709 is 90716555.

It is not a de Polignac number, because 55561709 - 2²⁰ = 54513133 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 (55561409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38057 + ... + 39489.

It is an arithmetic number, because the mean of its divisors is an integer number (4129920).

Almost surely, 2^55561709 is an apocalyptic number.

It is an amenable number.

55561709 is a deficient number, since it is larger than the sum of its proper divisors (10517011).

55561709 is a wasteful number, since it uses less digits than its factorization.

55561709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660.

The product of its (nonzero) digits is 47250, while the sum is 38.

The square root of 55561709 is about 7453.9726991719. The cubic root of 55561709 is about 381.5855015353.

The spelling of 55561709 in words is "fifty-five million, five hundred sixty-one thousand, seven hundred nine".