3655840 has 48 divisors (see below), whose sum is σ = 8783208. Its totient is φ = 1437696.

The previous prime is 3655837. The next prime is 3655849. The reversal of 3655840 is 485563.

It can be written as a sum of positive squares in 4 ways, for example, as 1838736 + 1817104 = 1356^2 + 1348^2 .

It is a super-2 number, since 2×3655840² = 26730332211200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3655849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11524 + ... + 11836.

Almost surely, 2^3655840 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 3655840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4391604).

3655840 is an abundant number, since it is smaller than the sum of its proper divisors (5127368).

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

3655840 is a wasteful number, since it uses less digits than its factorization.

3655840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 3655840 is about 1912.0251044377. The cubic root of 3655840 is about 154.0502450318.

It can be divided in two parts, 365 and 5840, that multiplied together give a square (2131600 = 1460²).

The spelling of 3655840 in words is "three million, six hundred fifty-five thousand, eight hundred forty".