3685640 has 32 divisors (see below), whose sum is σ = 9478080. Its totient is φ = 1263552.

The previous prime is 3685631. The next prime is 3685657. The reversal of 3685640 is 465863.

3685640 = 123² + 124² + ... + 234².

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 3685597 and 3685606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6302 + ... + 6861.

It is an arithmetic number, because the mean of its divisors is an integer number (296190).

Almost surely, 2^3685640 is an apocalyptic number.

It is an amenable number.

3685640 is an abundant number, since it is smaller than the sum of its proper divisors (5792440).

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

3685640 is a wasteful number, since it uses less digits than its factorization.

3685640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13181 (or 13177 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 3685640 is about 1919.8020731315. The cubic root of 3685640 is about 154.4676848939.

The spelling of 3685640 in words is "three million, six hundred eighty-five thousand, six hundred forty".