681749406 has 32 divisors (see below), whose sum is σ = 1631538720. Its totient is φ = 209768832.

The previous prime is 681749377. The next prime is 681749413. The reversal of 681749406 is 604947186.

681749406 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 484875 + ... + 486278.

It is an arithmetic number, because the mean of its divisors is an integer number (50985585).

Almost surely, 2^681749406 is an apocalyptic number.

681749406 is an abundant number, since it is smaller than the sum of its proper divisors (949789314).

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

681749406 is a wasteful number, since it uses less digits than its factorization.

681749406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 971177 (or 971171 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 681749406 is about 26110.3314034885. The cubic root of 681749406 is about 880.1193906540.

The spelling of 681749406 in words is "six hundred eighty-one million, seven hundred forty-nine thousand, four hundred six".