3645520 has 20 divisors (see below), whose sum is σ = 8476020. Its totient is φ = 1458176.

The previous prime is 3645469. The next prime is 3645527. The reversal of 3645520 is 255463.

It can be written as a sum of positive squares in 2 ways, for example, as 2547216 + 1098304 = 1596^2 + 1048^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3645527) 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, 22705 + ... + 22864.

It is an arithmetic number, because the mean of its divisors is an integer number (423801).

Almost surely, 2^3645520 is an apocalyptic number.

It is an amenable number.

3645520 is an abundant number, since it is smaller than the sum of its proper divisors (4830500).

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

3645520 is a wasteful number, since it uses less digits than its factorization.

3645520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45582 (or 45576 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 25.

The square root of 3645520 is about 1909.3244878752. The cubic root of 3645520 is about 153.9051532685.

The spelling of 3645520 in words is "three million, six hundred forty-five thousand, five hundred twenty".