8421457 has 4 divisors (see below), whose sum is σ = 9187056. Its totient is φ = 7655860.

The previous prime is 8421419. The next prime is 8421463. The reversal of 8421457 is 7541248.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8421457 is a prime.

It is a d-powerful number, because it can be written as 8⁵ + 4 + 2²³ + 1 + 4³ + 5 + 7 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8421407) 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 3 ways as a sum of consecutive naturals, for example, 382783 + ... + 382804.

It is an arithmetic number, because the mean of its divisors is an integer number (2296764).

Almost surely, 2^8421457 is an apocalyptic number.

It is an amenable number.

8421457 is a deficient number, since it is larger than the sum of its proper divisors (765599).

8421457 is a wasteful number, since it uses less digits than its factorization.

8421457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765598.

The product of its digits is 8960, while the sum is 31.

The square root of 8421457 is about 2901.9746725290. The cubic root of 8421457 is about 203.4522100409.

The spelling of 8421457 in words is "eight million, four hundred twenty-one thousand, four hundred fifty-seven".