685979280 has 360 divisors, whose sum is σ = 2769364416. Its totient is φ = 154586880.

The previous prime is 685979263. The next prime is 685979293. The reversal of 685979280 is 82979586.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 9661645 + ... + 9661715.

Almost surely, 2^685979280 is an apocalyptic number.

685979280 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 685979280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1384682208).

685979280 is an abundant number, since it is smaller than the sum of its proper divisors (2083385136).

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

685979280 is an equidigital number, since it uses as much as digits as its factorization.

685979280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The square root of 685979280 is about 26191.2061577927. The cubic root of 685979280 is about 881.9358553934.

685979280 divided by its sum of digits (54) gives a triangular number (12703320 = T₅₀₄₀).

It can be divided in two parts, 68597 and 9280, that added together give a palindrome (77877).

The spelling of 685979280 in words is "six hundred eighty-five million, nine hundred seventy-nine thousand, two hundred eighty".