665666169 has 8 divisors (see below), whose sum is σ = 1014348480. Its totient is φ = 380380656.

The previous prime is 665666129. The next prime is 665666171. The reversal of 665666169 is 961666566.

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

It is not a de Polignac number, because 665666169 - 2⁷ = 665666041 is a prime.

It is a super-2 number, since 2×665666169² = 886222897102273122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665666129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15849174 + ... + 15849215.

It is an arithmetic number, because the mean of its divisors is an integer number (126793560).

Almost surely, 2^665666169 is an apocalyptic number.

It is an amenable number.

665666169 is a deficient number, since it is larger than the sum of its proper divisors (348682311).

665666169 is a wasteful number, since it uses less digits than its factorization.

665666169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31698399.

The product of its digits is 2099520, while the sum is 51.

The square root of 665666169 is about 25800.5071461783. The cubic root of 665666169 is about 873.1432383330.

The spelling of 665666169 in words is "six hundred sixty-five million, six hundred sixty-six thousand, one hundred sixty-nine".