3645640 has 16 divisors (see below), whose sum is σ = 8202780. Its totient is φ = 1458240.

The previous prime is 3645623. The next prime is 3645643. The reversal of 3645640 is 465463.

It can be written as a sum of positive squares in 2 ways, for example, as 3334276 + 311364 = 1826^2 + 558^2 .

It is a d-powerful number, because it can be written as 3 + 6⁵ + 4⁵ + 5⁹ + 6⁸ + 4⁶ + 0 .

It is a junction number, because it is equal to n+sod(n) for n = 3645599 and 3645608.

It is not an unprimeable number, because it can be changed into a prime (3645643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45531 + ... + 45610.

Almost surely, 2^3645640 is an apocalyptic number.

It is an amenable number.

3645640 is an abundant number, since it is smaller than the sum of its proper divisors (4557140).

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

3645640 is a wasteful number, since it uses less digits than its factorization.

3645640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91152 (or 91148 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 3645640 is about 1909.3559123432. The cubic root of 3645640 is about 153.9068419545.

The spelling of 3645640 in words is "three million, six hundred forty-five thousand, six hundred forty".