3645021 has 8 divisors (see below), whose sum is σ = 5145984. Its totient is φ = 2287040.

The previous prime is 3645013. The next prime is 3645049. The reversal of 3645021 is 1205463.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3645021 - 2³ = 3645013 is a prime.

It is a Curzon number.

3645021 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3645071) 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, 35685 + ... + 35786.

It is an arithmetic number, because the mean of its divisors is an integer number (643248).

Almost surely, 2^3645021 is an apocalyptic number.

It is an amenable number.

3645021 is a deficient number, since it is larger than the sum of its proper divisors (1500963).

3645021 is a wasteful number, since it uses less digits than its factorization.

3645021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71491.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 3645021 is about 1909.1938089152. The cubic root of 3645021 is about 153.8981307517.

The spelling of 3645021 in words is "three million, six hundred forty-five thousand, twenty-one".