55685909 has 2 divisors, whose sum is σ = 55685910. Its totient is φ = 55685908.

The previous prime is 55685891. The next prime is 55685947. The reversal of 55685909 is 90958655.

55685909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49420900 + 6265009 = 7030^2 + 2503^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55685909 is a prime.

It is a super-2 number, since 2×55685909² = 6201840922312562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55685969) 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 as a sum of consecutive naturals, namely, 27842954 + 27842955.

It is an arithmetic number, because the mean of its divisors is an integer number (27842955).

Almost surely, 2^55685909 is an apocalyptic number.

It is an amenable number.

55685909 is a deficient number, since it is larger than the sum of its proper divisors (1).

55685909 is an equidigital number, since it uses as much as digits as its factorization.

55685909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486000, while the sum is 47.

The square root of 55685909 is about 7462.2991765273. The cubic root of 55685909 is about 381.8696159650.

The spelling of 55685909 in words is "fifty-five million, six hundred eighty-five thousand, nine hundred nine".