685128455 has 16 divisors (see below), whose sum is σ = 897499008. Its totient is φ = 497940000.

The previous prime is 685128421. The next prime is 685128461. The reversal of 685128455 is 554821586.

685128455 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 685128455 - 2¹² = 685124359 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, 102980 + ... + 109430.

It is an arithmetic number, because the mean of its divisors is an integer number (56093688).

Almost surely, 2^685128455 is an apocalyptic number.

685128455 is a deficient number, since it is larger than the sum of its proper divisors (212370553).

685128455 is a wasteful number, since it uses less digits than its factorization.

685128455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8398.

The product of its digits is 384000, while the sum is 44.

The square root of 685128455 is about 26174.9585482002. The cubic root of 685128455 is about 881.5710807610.

It can be divided in two parts, 68512 and 8455, that added together give a palindrome (76967).

The spelling of 685128455 in words is "six hundred eighty-five million, one hundred twenty-eight thousand, four hundred fifty-five".