665840201 has 8 divisors (see below), whose sum is σ = 727159104. Its totient is φ = 605964240.

The previous prime is 665840143. The next prime is 665840209. The reversal of 665840201 is 102048566.

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 665840201 - 2⁶ = 665840137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665840209) 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, 359771 + ... + 361616.

It is an arithmetic number, because the mean of its divisors is an integer number (90894888).

Almost surely, 2^665840201 is an apocalyptic number.

It is an amenable number.

665840201 is a deficient number, since it is larger than the sum of its proper divisors (61318903).

665840201 is a wasteful number, since it uses less digits than its factorization.

665840201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721471.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 665840201 is about 25803.8795726534. The cubic root of 665840201 is about 873.2193233291.

Adding to 665840201 its reverse (102048566), we get a palindrome (767888767).

The spelling of 665840201 in words is "six hundred sixty-five million, eight hundred forty thousand, two hundred one".