66600005 has 4 divisors (see below), whose sum is σ = 79920012. Its totient is φ = 53280000.

The previous prime is 66599989. The next prime is 66600029. The reversal of 66600005 is 50000666.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 32878756 + 33721249 = 5734^2 + 5807^2 .

It is not a de Polignac number, because 66600005 - 2⁴ = 66599989 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 6659996 + ... + 6660005.

It is an arithmetic number, because the mean of its divisors is an integer number (19980003).

Almost surely, 2^66600005 is an apocalyptic number.

It is an amenable number.

66600005 is a deficient number, since it is larger than the sum of its proper divisors (13320007).

66600005 is a wasteful number, since it uses less digits than its factorization.

66600005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13320006.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 66600005 is about 8160.8826115807. The cubic root of 66600005 is about 405.3449380593.

The spelling of 66600005 in words is "sixty-six million, six hundred thousand, five".