3658640 has 80 divisors (see below), whose sum is σ = 9374400. Its totient is φ = 1322496.

The previous prime is 3658639. The next prime is 3658661. The reversal of 3658640 is 468563.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 3658597 and 3658606.

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, 44039 + ... + 44121.

It is an arithmetic number, because the mean of its divisors is an integer number (117180).

Almost surely, 2^3658640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3658640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4687200).

3658640 is an abundant number, since it is smaller than the sum of its proper divisors (5715760).

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

3658640 is a wasteful number, since it uses less digits than its factorization.

3658640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 138 counting only the distinct ones).

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

The square root of 3658640 is about 1912.7571722516. The cubic root of 3658640 is about 154.0895639127.

The spelling of 3658640 in words is "three million, six hundred fifty-eight thousand, six hundred forty".