8642421 has 12 divisors (see below), whose sum is σ = 12606048. Its totient is φ = 5705064.

The previous prime is 8642383. The next prime is 8642429. The reversal of 8642421 is 1242468.

It is not a de Polignac number, because 8642421 - 2⁹ = 8641909 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8642429) 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, 3735 + ... + 5588.

It is an arithmetic number, because the mean of its divisors is an integer number (1050504).

Almost surely, 2^8642421 is an apocalyptic number.

It is an amenable number.

8642421 is a deficient number, since it is larger than the sum of its proper divisors (3963627).

8642421 is a wasteful number, since it uses less digits than its factorization.

8642421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9432 (or 9429 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 8642421 is about 2939.7994829580. The cubic root of 8642421 is about 205.2162777917.

Adding to 8642421 its reverse (1242468), we get a palindrome (9884889).

The spelling of 8642421 in words is "eight million, six hundred forty-two thousand, four hundred twenty-one".