665515555 has 8 divisors (see below), whose sum is σ = 799174800. Its totient is φ = 532041696.

The previous prime is 665515553. The next prime is 665515561. The reversal of 665515555 is 555515566.

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 665515555 - 2¹ = 665515553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665515553) 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, 38320 + ... + 52909.

It is an arithmetic number, because the mean of its divisors is an integer number (99896850).

Almost surely, 2^665515555 is an apocalyptic number.

665515555 is a deficient number, since it is larger than the sum of its proper divisors (133659245).

665515555 is a wasteful number, since it uses less digits than its factorization.

665515555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92693.

The product of its digits is 562500, while the sum is 43.

The square root of 665515555 is about 25797.5881624620. The cubic root of 665515555 is about 873.0773807398.

The spelling of 665515555 in words is "six hundred sixty-five million, five hundred fifteen thousand, five hundred fifty-five".