3989821 has 8 divisors (see below), whose sum is σ = 4470624. Its totient is φ = 3528720.

The previous prime is 3989809. The next prime is 3989831. The reversal of 3989821 is 1289893.

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 3989821 - 2¹³ = 3981629 is a prime.

It is a super-2 number, since 2×3989821² = 31837343224082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3989801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4495 + ... + 5308.

It is an arithmetic number, because the mean of its divisors is an integer number (558828).

Almost surely, 2^3989821 is an apocalyptic number.

It is an amenable number.

3989821 is a deficient number, since it is larger than the sum of its proper divisors (480803).

3989821 is a wasteful number, since it uses less digits than its factorization.

3989821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9851.

The product of its digits is 31104, while the sum is 40.

The square root of 3989821 is about 1997.4536289987. The cubic root of 3989821 is about 158.6053395229.

The spelling of 3989821 in words is "three million, nine hundred eighty-nine thousand, eight hundred twenty-one".