55661666 has 8 divisors (see below), whose sum is σ = 83842560. Its totient is φ = 27714148.

The previous prime is 55661629. The next prime is 55661699. The reversal of 55661666 is 66616655.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57746 + ... + 58701.

It is an arithmetic number, because the mean of its divisors is an integer number (10480320).

Almost surely, 2^55661666 is an apocalyptic number.

55661666 is a deficient number, since it is larger than the sum of its proper divisors (28180894).

55661666 is a wasteful number, since it uses less digits than its factorization.

55661666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116688.

The product of its digits is 194400, while the sum is 41.

The square root of 55661666 is about 7460.6746343746. The cubic root of 55661666 is about 381.8141919565.

The spelling of 55661666 in words is "fifty-five million, six hundred sixty-one thousand, six hundred sixty-six".