406785 has 16 divisors (see below), whose sum is σ = 665856. Its totient is φ = 211968.

The previous prime is 406739. The next prime is 406789. The reversal of 406785 is 587604.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-406785 is a prime.

It is not an unprimeable number, because it can be changed into a prime (406789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 417 + ... + 993.

It is an arithmetic number, because the mean of its divisors is an integer number (41616).

2⁴⁰⁶⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

406785 is a deficient number, since it is larger than the sum of its proper divisors (259071).

406785 is a wasteful number, since it uses less digits than its factorization.

406785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 406785 is about 637.7969896448. The cubic root of 406785 is about 74.0948989442.

Subtracting from 406785 its product of nonzero digits (6720), we obtain a triangular number (400065 = T₈₉₄).

The spelling of 406785 in words is "four hundred six thousand, seven hundred eighty-five".