665615017 has 4 divisors (see below), whose sum is σ = 681094480. Its totient is φ = 650135556.

The previous prime is 665615003. The next prime is 665615023. The reversal of 665615017 is 710516566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 665615017 - 2¹⁹ = 665090729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665615057) 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 3 ways as a sum of consecutive naturals, for example, 7739667 + ... + 7739752.

It is an arithmetic number, because the mean of its divisors is an integer number (170273620).

Almost surely, 2^665615017 is an apocalyptic number.

It is an amenable number.

665615017 is a deficient number, since it is larger than the sum of its proper divisors (15479463).

665615017 is a wasteful number, since it uses less digits than its factorization.

665615017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15479462.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 665615017 is about 25799.5158287903. The cubic root of 665615017 is about 873.1208726843.

The spelling of 665615017 in words is "six hundred sixty-five million, six hundred fifteen thousand, seventeen".