685943640 has 80 divisors (see below), whose sum is σ = 2305543680. Its totient is φ = 182917440.

The previous prime is 685943639. The next prime is 685943683. The reversal of 685943640 is 46349586.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 102616 + ... + 109095.

It is an arithmetic number, because the mean of its divisors is an integer number (28819296).

Almost surely, 2^685943640 is an apocalyptic number.

685943640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

685943640 is an abundant number, since it is smaller than the sum of its proper divisors (1619600040).

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

685943640 is a wasteful number, since it uses less digits than its factorization.

685943640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211734 (or 211721 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 685943640 is about 26190.5257679184. The cubic root of 685943640 is about 881.9205814927.

The spelling of 685943640 in words is "six hundred eighty-five million, nine hundred forty-three thousand, six hundred forty".