3644643 has 12 divisors (see below), whose sum is σ = 4949384. Its totient is φ = 2385600.

The previous prime is 3644629. The next prime is 3644653. The reversal of 3644643 is 3464463.

It is not a de Polignac number, because 3644643 - 2²⁰ = 2596067 is a prime.

It is an Ulam number.

It is a Duffinian number.

3644643 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3644643.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3644653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15003 + ... + 15243.

Almost surely, 2^3644643 is an apocalyptic number.

3644643 is a deficient number, since it is larger than the sum of its proper divisors (1304741).

3644643 is an equidigital number, since it uses as much as digits as its factorization.

3644643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 315 counting only the distinct ones).

The product of its digits is 20736, while the sum is 30.

The square root of 3644643 is about 1909.0948116843. The cubic root of 3644643 is about 153.8928106631.

The spelling of 3644643 in words is "three million, six hundred forty-four thousand, six hundred forty-three".