685390824 has 24 divisors (see below), whose sum is σ = 1856267010. Its totient is φ = 228463584.

The previous prime is 685390799. The next prime is 685390829. The reversal of 685390824 is 428093586.

It can be written as a sum of positive squares in only one way, i.e., 651168324 + 34222500 = 25518^2 + 5850^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 685390824.

It is not an unprimeable number, because it can be changed into a prime (685390829) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4759587 + ... + 4759730.

Almost surely, 2^685390824 is an apocalyptic number.

It is an amenable number.

685390824 is an abundant number, since it is smaller than the sum of its proper divisors (1170876186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685390824 is a wasteful number, since it uses less digits than its factorization.

685390824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9519329 (or 9519322 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 685390824 is about 26179.9699006702. The cubic root of 685390824 is about 881.6835985439.

The spelling of 685390824 in words is "six hundred eighty-five million, three hundred ninety thousand, eight hundred twenty-four".