8216421 has 8 divisors (see below), whose sum is σ = 10973664. Its totient is φ = 5468400.

The previous prime is 8216407. The next prime is 8216437. The reversal of 8216421 is 1246128.

8216421 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 8216421 - 2⁷ = 8216293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8216391 and 8216400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8216471) 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, 150 + ... + 4056.

It is an arithmetic number, because the mean of its divisors is an integer number (1371708).

Almost surely, 2^8216421 is an apocalyptic number.

It is an amenable number.

8216421 is a deficient number, since it is larger than the sum of its proper divisors (2757243).

8216421 is a wasteful number, since it uses less digits than its factorization.

8216421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4611.

The product of its digits is 768, while the sum is 24.

The square root of 8216421 is about 2866.4300096113. The cubic root of 8216421 is about 201.7874852229.

The spelling of 8216421 in words is "eight million, two hundred sixteen thousand, four hundred twenty-one".