665856331 has 8 divisors (see below), whose sum is σ = 775337184. Its totient is φ = 559965120.

The previous prime is 665856307. The next prime is 665856341. The reversal of 665856331 is 133658566.

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

It is a cyclic number.

It is not a de Polignac number, because 665856331 - 2⁷ = 665856203 is a prime.

It is a super-2 number, since 2×665856331² = 886729307065563122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665856341) 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, 897010 + ... + 897751.

It is an arithmetic number, because the mean of its divisors is an integer number (96917148).

Almost surely, 2^665856331 is an apocalyptic number.

665856331 is a deficient number, since it is larger than the sum of its proper divisors (109480853).

665856331 is a wasteful number, since it uses less digits than its factorization.

665856331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794821.

The product of its digits is 388800, while the sum is 43.

The square root of 665856331 is about 25804.1921206613. The cubic root of 665856331 is about 873.2263745274.

The spelling of 665856331 in words is "six hundred sixty-five million, eight hundred fifty-six thousand, three hundred thirty-one".