665660615 has 8 divisors (see below), whose sum is σ = 799519680. Its totient is φ = 532043872.

The previous prime is 665660603. The next prime is 665660617. The reversal of 665660615 is 516066566.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665660615 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665660617) 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, 54479 + ... + 65568.

It is an arithmetic number, because the mean of its divisors is an integer number (99939960).

Almost surely, 2^665660615 is an apocalyptic number.

665660615 is a deficient number, since it is larger than the sum of its proper divisors (133859065).

665660615 is a wasteful number, since it uses less digits than its factorization.

665660615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121161.

The product of its (nonzero) digits is 194400, while the sum is 41.

The square root of 665660615 is about 25800.3995124107. The cubic root of 665660615 is about 873.1408099631.

The spelling of 665660615 in words is "six hundred sixty-five million, six hundred sixty thousand, six hundred fifteen".