405840685 has 16 divisors (see below), whose sum is σ = 505308672. Its totient is φ = 312580800.

The previous prime is 405840671. The next prime is 405840691. The reversal of 405840685 is 586048504.

It is not a de Polignac number, because 405840685 - 2¹⁷ = 405709613 is a prime.

It is a Duffinian number.

It is a congruent 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, 23890 + ... + 37180.

It is an arithmetic number, because the mean of its divisors is an integer number (31581792).

Almost surely, 2^405840685 is an apocalyptic number.

It is an amenable number.

405840685 is a deficient number, since it is larger than the sum of its proper divisors (99467987).

405840685 is a wasteful number, since it uses less digits than its factorization.

405840685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13524.

The product of its (nonzero) digits is 153600, while the sum is 40.

The square root of 405840685 is about 20145.4879563638. The cubic root of 405840685 is about 740.3751962703.

The spelling of 405840685 in words is "four hundred five million, eight hundred forty thousand, six hundred eighty-five".