409965 has 16 divisors (see below), whose sum is σ = 663936. Its totient is φ = 216000.

The previous prime is 409961. The next prime is 409967. The reversal of 409965 is 569904.

It is a happy number.

409965 is a nontrivial binomial coefficient, being equal to C(906, 2).

It is not a de Polignac number, because 409965 - 2² = 409961 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2175 + ... + 2355.

It is an arithmetic number, because the mean of its divisors is an integer number (41496).

2⁴⁰⁹⁹⁶⁵ is an apocalyptic number.

409965 is the 905-th triangular number and also the 453-rd hexagonal number.

It is an amenable number.

409965 is a deficient number, since it is larger than the sum of its proper divisors (253971).

409965 is a wasteful number, since it uses less digits than its factorization.

409965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 409965 is about 640.2850927517. The cubic root of 409965 is about 74.2874744229.

The spelling of 409965 in words is "four hundred nine thousand, nine hundred sixty-five".