8406021 has 16 divisors (see below), whose sum is σ = 12254144. Its totient is φ = 5094144.

The previous prime is 8406001. The next prime is 8406043. The reversal of 8406021 is 1206048.

It is not a de Polignac number, because 8406021 - 2¹⁰ = 8404997 is a prime.

It is a super-2 number, since 2×8406021² = 141322378104882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8406001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1005 + ... + 4221.

It is an arithmetic number, because the mean of its divisors is an integer number (765884).

Almost surely, 2^8406021 is an apocalyptic number.

It is an amenable number.

8406021 is a deficient number, since it is larger than the sum of its proper divisors (3848123).

8406021 is a wasteful number, since it uses less digits than its factorization.

8406021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3300.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 8406021 is about 2899.3138843526. The cubic root of 8406021 is about 203.3278289889.

The spelling of 8406021 in words is "eight million, four hundred six thousand, twenty-one".