3818821 has 4 divisors (see below), whose sum is σ = 3835872. Its totient is φ = 3801772.

The previous prime is 3818803. The next prime is 3818831. The reversal of 3818821 is 1288183.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3818821 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

3818821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3818831) 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, 8185 + ... + 8638.

It is an arithmetic number, because the mean of its divisors is an integer number (958968).

Almost surely, 2^3818821 is an apocalyptic number.

It is an amenable number.

3818821 is a deficient number, since it is larger than the sum of its proper divisors (17051).

3818821 is a wasteful number, since it uses less digits than its factorization.

3818821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17050.

The product of its digits is 3072, while the sum is 31.

The square root of 3818821 is about 1954.1803908544. The cubic root of 3818821 is about 156.3062824442.

The spelling of 3818821 in words is "three million, eight hundred eighteen thousand, eight hundred twenty-one".