685729920 has 256 divisors, whose sum is σ = 2319528960. Its totient is φ = 172032000.

The previous prime is 685729909. The next prime is 685729927. The reversal of 685729920 is 29927586.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 685729920.

It is not an unprimeable number, because it can be changed into a prime (685729927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2440180 + ... + 2440460.

It is an arithmetic number, because the mean of its divisors is an integer number (9060660).

Almost surely, 2^685729920 is an apocalyptic number.

685729920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685729920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1159764480).

685729920 is an abundant number, since it is smaller than the sum of its proper divisors (1633799040).

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

685729920 is a wasteful number, since it uses less digits than its factorization.

685729920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 48.

The square root of 685729920 is about 26186.4453486914. The cubic root of 685729920 is about 881.8289784151.

The spelling of 685729920 in words is "six hundred eighty-five million, seven hundred twenty-nine thousand, nine hundred twenty".