665662551 has 8 divisors (see below), whose sum is σ = 906434304. Its totient is φ = 434332920.

The previous prime is 665662541. The next prime is 665662553. The reversal of 665662551 is 155266566.

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

It is not a de Polignac number, because 665662551 - 2⁵ = 665662519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665662553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2360365 + ... + 2360646.

It is an arithmetic number, because the mean of its divisors is an integer number (113304288).

Almost surely, 2^665662551 is an apocalyptic number.

665662551 is a deficient number, since it is larger than the sum of its proper divisors (240771753).

665662551 is a wasteful number, since it uses less digits than its factorization.

665662551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4721061.

The product of its digits is 324000, while the sum is 42.

The square root of 665662551 is about 25800.4370311822. The cubic root of 665662551 is about 873.1416564400.

The spelling of 665662551 in words is "six hundred sixty-five million, six hundred sixty-two thousand, five hundred fifty-one".