660405 has 8 divisors (see below), whose sum is σ = 1056672. Its totient is φ = 352208.

The previous prime is 660403. The next prime is 660409. The reversal of 660405 is 504066.

660405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 660405 - 2¹ = 660403 is a prime.

It is a super-2 number, since 2×660405² = 872269528050, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21999 + ... + 22028.

It is an arithmetic number, because the mean of its divisors is an integer number (132084).

2⁶⁶⁰⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

660405 is a deficient number, since it is larger than the sum of its proper divisors (396267).

660405 is a wasteful number, since it uses less digits than its factorization.

660405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44035.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 660405 is about 812.6530625058. The cubic root of 660405 is about 87.0836821996.

The spelling of 660405 in words is "six hundred sixty thousand, four hundred five".