66721219106 has 8 divisors (see below), whose sum is σ = 100177238700. Its totient is φ = 33328806208.

The previous prime is 66721219069. The next prime is 66721219153. The reversal of 66721219106 is 60191212766.

It can be written as a sum of positive squares in 2 ways, for example, as 65287915225 + 1433303881 = 255515^2 + 37859^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15899051 + ... + 15903246.

Almost surely, 2^66721219106 is an apocalyptic number.

66721219106 is a deficient number, since it is larger than the sum of its proper divisors (33456019594).

66721219106 is a wasteful number, since it uses less digits than its factorization.

66721219106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31803348.

The product of its (nonzero) digits is 54432, while the sum is 41.

The spelling of 66721219106 in words is "sixty-six billion, seven hundred twenty-one million, two hundred nineteen thousand, one hundred six".