3621639 has 24 divisors (see below), whose sum is σ = 5712768. Its totient is φ = 2034480.

The previous prime is 3621623. The next prime is 3621643. The reversal of 3621639 is 9361263.

It is a happy number.

3621639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3621639 - 2⁴ = 3621623 is a prime.

3621639 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3621139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10264 + ... + 10610.

It is an arithmetic number, because the mean of its divisors is an integer number (238032).

Almost surely, 2^3621639 is an apocalyptic number.

3621639 is a deficient number, since it is larger than the sum of its proper divisors (2091129).

3621639 is a wasteful number, since it uses less digits than its factorization.

3621639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435 (or 428 counting only the distinct ones).

The product of its digits is 5832, while the sum is 30.

The square root of 3621639 is about 1903.0604299391. The cubic root of 3621639 is about 153.5683504804.

Adding to 3621639 its product of digits (5832), we get a triangular number (3627471 = T₂₆₉₃).

The spelling of 3621639 in words is "three million, six hundred twenty-one thousand, six hundred thirty-nine".