684871940 has 12 divisors (see below), whose sum is σ = 1438231116. Its totient is φ = 273948768.

The previous prime is 684871937. The next prime is 684871951. The reversal of 684871940 is 49178486.

It can be written as a sum of positive squares in 2 ways, for example, as 290293444 + 394578496 = 17038^2 + 19864^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17121779 + ... + 17121818.

It is an arithmetic number, because the mean of its divisors is an integer number (119852593).

Almost surely, 2^684871940 is an apocalyptic number.

It is an amenable number.

684871940 is an abundant number, since it is smaller than the sum of its proper divisors (753359176).

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

684871940 is a wasteful number, since it uses less digits than its factorization.

684871940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34243606 (or 34243604 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 47.

The square root of 684871940 is about 26170.0580817086. The cubic root of 684871940 is about 881.4610457098.

The spelling of 684871940 in words is "six hundred eighty-four million, eight hundred seventy-one thousand, nine hundred forty".