8442021 has 16 divisors (see below), whose sum is σ = 12940928. Its totient is φ = 4795200.

The previous prime is 8442011. The next prime is 8442029. The reversal of 8442021 is 1202448.

8442021 = T₈ + T₉ + ... + T₃₆₉.

It is a de Polignac number, because none of the positive numbers 2^k-8442021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8442029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2691 + ... + 4911.

It is an arithmetic number, because the mean of its divisors is an integer number (808808).

Almost surely, 2^8442021 is an apocalyptic number.

It is an amenable number.

8442021 is a deficient number, since it is larger than the sum of its proper divisors (4498907).

8442021 is a wasteful number, since it uses less digits than its factorization.

8442021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2412.

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 8442021 is about 2905.5156168914. The cubic root of 8442021 is about 203.6176758842.

Adding to 8442021 its reverse (1202448), we get a palindrome (9644469).

The spelling of 8442021 in words is "eight million, four hundred forty-two thousand, twenty-one".