8642021 has 12 divisors (see below), whose sum is σ = 9118116. Its totient is φ = 8186880.

The previous prime is 8642003. The next prime is 8642027. The reversal of 8642021 is 1202468.

It can be written as a sum of positive squares in 6 ways, for example, as 1809025 + 6832996 = 1345^2 + 2614^2 .

It is not a de Polignac number, because 8642021 - 2⁶ = 8641957 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 (8642027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89045 + ... + 89141.

It is an arithmetic number, because the mean of its divisors is an integer number (759843).

Almost surely, 2^8642021 is an apocalyptic number.

It is an amenable number.

8642021 is a deficient number, since it is larger than the sum of its proper divisors (476095).

8642021 is an equidigital number, since it uses as much as digits as its factorization.

8642021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 8642021 is about 2939.7314503199. The cubic root of 8642021 is about 205.2131117122.

Adding to 8642021 its reverse (1202468), we get a palindrome (9844489).

The spelling of 8642021 in words is "eight million, six hundred forty-two thousand, twenty-one".