55666999 has 4 divisors (see below), whose sum is σ = 55683936. Its totient is φ = 55650064.

The previous prime is 55666997. The next prime is 55667011. The reversal of 55666999 is 99966655.

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

It is a cyclic number.

It is not a de Polignac number, because 55666999 - 2¹ = 55666997 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55666991) 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, 1774 + ... + 10699.

It is an arithmetic number, because the mean of its divisors is an integer number (13920984).

Almost surely, 2^55666999 is an apocalyptic number.

55666999 is a deficient number, since it is larger than the sum of its proper divisors (16937).

55666999 is a wasteful number, since it uses less digits than its factorization.

55666999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16936.

The product of its digits is 3936600, while the sum is 55.

The square root of 55666999 is about 7461.0320331707. The cubic root of 55666999 is about 381.8263855672.

It can be divided in two parts, 55666 and 999, that added together give a palindrome (56665).

The spelling of 55666999 in words is "fifty-five million, six hundred sixty-six thousand, nine hundred ninety-nine".