685665868800 has 528 divisors, whose sum is σ = 2617653030912. Its totient is φ = 156440985600.

The previous prime is 685665868793. The next prime is 685665868801. The reversal of 685665868800 is 8868566586.

685665868800 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (528).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685665868801) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14337729 + ... + 14385471.

Almost surely, 2^685665868800 is an apocalyptic number.

685665868800 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 685665868800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1308826515456).

685665868800 is an abundant number, since it is smaller than the sum of its proper divisors (1931987162112).

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

685665868800 is a wasteful number, since it uses less digits than its factorization.

685665868800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47804 (or 47781 counting only the distinct ones).

The product of its (nonzero) digits is 132710400, while the sum is 66.

The spelling of 685665868800 in words is "six hundred eighty-five billion, six hundred sixty-five million, eight hundred sixty-eight thousand, eight hundred".