685185408 has 192 divisors, whose sum is σ = 2126638800. Its totient is φ = 210960384.

The previous prime is 685185401. The next prime is 685185409. The reversal of 685185408 is 804581586.

685185408 is a `hidden beast` number, since 68 + 5 + 185 + 408 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-2 number, since 2×685185408² = 938958086672252928, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685185401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1155160 + ... + 1155752.

Almost surely, 2^685185408 is an apocalyptic number.

685185408 is a gapful number since it is divisible by the number (68) 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 685185408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1063319400).

685185408 is an abundant number, since it is smaller than the sum of its proper divisors (1441453392).

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

685185408 is a wasteful number, since it uses less digits than its factorization.

685185408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 45.

The square root of 685185408 is about 26176.0464547265. The cubic root of 685185408 is about 881.5955076775.

The spelling of 685185408 in words is "six hundred eighty-five million, one hundred eighty-five thousand, four hundred eight".