405128685 has 16 divisors (see below), whose sum is σ = 698068224. Its totient is φ = 199447872.

The previous prime is 405128663. The next prime is 405128687. The reversal of 405128685 is 586821504.

It is not a de Polignac number, because 405128685 - 2⁵ = 405128653 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405128687) 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, 1038597 + ... + 1038986.

It is an arithmetic number, because the mean of its divisors is an integer number (43629264).

Almost surely, 2^405128685 is an apocalyptic number.

It is an amenable number.

405128685 is a deficient number, since it is larger than the sum of its proper divisors (292939539).

405128685 is a wasteful number, since it uses less digits than its factorization.

405128685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2077604.

The product of its (nonzero) digits is 76800, while the sum is 39.

The square root of 405128685 is about 20127.8087480977. The cubic root of 405128685 is about 739.9419756062.

The spelling of 405128685 in words is "four hundred five million, one hundred twenty-eight thousand, six hundred eighty-five".