821218 has 8 divisors (see below), whose sum is σ = 1296720. Its totient is φ = 388980.

The previous prime is 821209. The next prime is 821263. The reversal of 821218 is 812128.

821218 is digitally balanced in base 2, 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 a plaindrome in base 15.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10768 + ... + 10843.

It is an arithmetic number, because the mean of its divisors is an integer number (162090).

2⁸²¹²¹⁸ is an apocalyptic number.

821218 is a deficient number, since it is larger than the sum of its proper divisors (475502).

821218 is a wasteful number, since it uses less digits than its factorization.

821218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21632.

The product of its digits is 256, while the sum is 22.

The square root of 821218 is about 906.2107922553. The cubic root of 821218 is about 93.6453362325.

It can be divided in two parts, 8 and 21218, that multiplied together give a square (169744 = 412²).

The spelling of 821218 in words is "eight hundred twenty-one thousand, two hundred eighteen".