665701 has 4 divisors (see below), whose sum is σ = 669600. Its totient is φ = 661804.

The previous prime is 665677. The next prime is 665713. The reversal of 665701 is 107566.

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, and also an emirpimes, since its reverse is a distinct semiprime: 107566 = 2 ⋅53783.

It is a cyclic number.

It is not a de Polignac number, because 665701 - 2⁷ = 665573 is a prime.

It is a Duffinian number.

665701 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1681 + ... + 2038.

It is an arithmetic number, because the mean of its divisors is an integer number (167400).

2⁶⁶⁵⁷⁰¹ is an apocalyptic number.

It is an amenable number.

665701 is a deficient number, since it is larger than the sum of its proper divisors (3899).

665701 is a wasteful number, since it uses less digits than its factorization.

665701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3898.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 665701 is about 815.9050189820. The cubic root of 665701 is about 87.3158467148.

The spelling of 665701 in words is "six hundred sixty-five thousand, seven hundred one".