66549955 has 4 divisors (see below), whose sum is σ = 79859952. Its totient is φ = 53239960.

The previous prime is 66549947. The next prime is 66549991. The reversal of 66549955 is 55994566.

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

It is not a de Polignac number, because 66549955 - 2³ = 66549947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66549899 and 66549908.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6654991 + ... + 6655000.

It is an arithmetic number, because the mean of its divisors is an integer number (19964988).

Almost surely, 2^66549955 is an apocalyptic number.

66549955 is a deficient number, since it is larger than the sum of its proper divisors (13309997).

66549955 is a wasteful number, since it uses less digits than its factorization.

66549955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13309996.

The product of its digits is 1458000, while the sum is 49.

The square root of 66549955 is about 8157.8155777144. The cubic root of 66549955 is about 405.2433735108.

The spelling of 66549955 in words is "sixty-six million, five hundred forty-nine thousand, nine hundred fifty-five".