8440421 has 8 divisors (see below), whose sum is σ = 9525600. Its totient is φ = 7408240.

The previous prime is 8440391. The next prime is 8440423. The reversal of 8440421 is 1240448.

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 8440421 - 2⁶ = 8440357 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 (8440423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12911 + ... + 13548.

It is an arithmetic number, because the mean of its divisors is an integer number (1190700).

Almost surely, 2^8440421 is an apocalyptic number.

It is an amenable number.

8440421 is a deficient number, since it is larger than the sum of its proper divisors (1085179).

8440421 is a wasteful number, since it uses less digits than its factorization.

8440421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26499.

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 8440421 is about 2905.2402654514. The cubic root of 8440421 is about 203.6048113159.

Adding to 8440421 its reverse (1240448), we get a palindrome (9680869).

The spelling of 8440421 in words is "eight million, four hundred forty thousand, four hundred twenty-one".