55209666 has 8 divisors (see below), whose sum is σ = 110419344. Its totient is φ = 18403220.

The previous prime is 55209619. The next prime is 55209673. The reversal of 55209666 is 66690255.

55209666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

55209666 is an admirable number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 4600800 + ... + 4600811.

It is an arithmetic number, because the mean of its divisors is an integer number (13802418).

Almost surely, 2^55209666 is an apocalyptic number.

55209666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55209666 is a wasteful number, since it uses less digits than its factorization.

55209666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9201616.

The product of its (nonzero) digits is 97200, while the sum is 39.

The square root of 55209666 is about 7430.3207198613. The cubic root of 55209666 is about 380.7778756374. Note that the first 3 decimals are identical.

The spelling of 55209666 in words is "fifty-five million, two hundred nine thousand, six hundred sixty-six".