66005669 has 4 divisors (see below), whose sum is σ = 67789644. Its totient is φ = 64221696.

The previous prime is 66005663. The next prime is 66005683. The reversal of 66005669 is 96650066.

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 56776225 + 9229444 = 7535^2 + 3038^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66005669 is a prime.

It is a super-2 number, since 2×66005669² = 8713496680275122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66005663) 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, 891932 + ... + 892005.

It is an arithmetic number, because the mean of its divisors is an integer number (16947411).

Almost surely, 2^66005669 is an apocalyptic number.

It is an amenable number.

66005669 is a deficient number, since it is larger than the sum of its proper divisors (1783975).

66005669 is a wasteful number, since it uses less digits than its factorization.

66005669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783974.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 66005669 is about 8124.3872999753. The cubic root of 66005669 is about 404.1355723318.

The spelling of 66005669 in words is "sixty-six million, five thousand, six hundred sixty-nine".