3656640 has 112 divisors (see below), whose sum is σ = 12545568. Its totient is φ = 897024.

The previous prime is 3656633. The next prime is 3656641. The reversal of 3656640 is 466563.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 3656598 and 3656607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3656641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12334 + ... + 12626.

It is an arithmetic number, because the mean of its divisors is an integer number (112014).

Almost surely, 2^3656640 is an apocalyptic number.

3656640 is a gapful number since it is divisible by the number (30) 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 3656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6272784).

3656640 is an abundant number, since it is smaller than the sum of its proper divisors (8888928).

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

3656640 is a wasteful number, since it uses less digits than its factorization.

3656640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 3656640 is about 1912.2342952682. The cubic root of 3656640 is about 154.0614810458.

The spelling of 3656640 in words is "three million, six hundred fifty-six thousand, six hundred forty".