3638821 has 8 divisors (see below), whose sum is σ = 3763584. Its totient is φ = 3516240.

The previous prime is 3638809. The next prime is 3638827. The reversal of 3638821 is 1288363.

3638821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 3638821 - 2¹³ = 3630629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3638827) 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 7 ways as a sum of consecutive naturals, for example, 3280 + ... + 4246.

It is an arithmetic number, because the mean of its divisors is an integer number (470448).

Almost surely, 2^3638821 is an apocalyptic number.

It is an amenable number.

3638821 is a deficient number, since it is larger than the sum of its proper divisors (124763).

3638821 is an equidigital number, since it uses as much as digits as its factorization.

3638821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1091.

The product of its digits is 6912, while the sum is 31.

The square root of 3638821 is about 1907.5693958543. The cubic root of 3638821 is about 153.8108235346.

It can be divided in two parts, 363 and 8821, that multiplied together give a palindrome (3202023).

The spelling of 3638821 in words is "three million, six hundred thirty-eight thousand, eight hundred twenty-one".