665717705 has 16 divisors (see below), whose sum is σ = 859726224. Its totient is φ = 493025280.

The previous prime is 665717699. The next prime is 665717711. The reversal of 665717705 is 507717566.

It is an interprime number because it is at equal distance from previous prime (665717699) and next prime (665717711).

It can be written as a sum of positive squares in 8 ways, for example, as 284089 + 665433616 = 533^2 + 25796^2 .

It is not a de Polignac number, because 665717705 - 2⁶ = 665717641 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59012 + ... + 69381.

It is an arithmetic number, because the mean of its divisors is an integer number (53732889).

Almost surely, 2^665717705 is an apocalyptic number.

It is an amenable number.

665717705 is a deficient number, since it is larger than the sum of its proper divisors (194008519).

665717705 is a wasteful number, since it uses less digits than its factorization.

665717705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128476.

The product of its (nonzero) digits is 308700, while the sum is 44.

The square root of 665717705 is about 25801.5058669063. The cubic root of 665717705 is about 873.1657707228.

The spelling of 665717705 in words is "six hundred sixty-five million, seven hundred seventeen thousand, seven hundred five".