421818 has 16 divisors (see below), whose sum is σ = 850080. Its totient is φ = 139536.

The previous prime is 421807. The next prime is 421831. The reversal of 421818 is 818124.

421818 is a modest number, since divided by 1818 gives 42 as remainder.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1221 + ... + 1527.

It is an arithmetic number, because the mean of its divisors is an integer number (53130).

2⁴²¹⁸¹⁸ is an apocalyptic number.

421818 is an abundant number, since it is smaller than the sum of its proper divisors (428262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421818 is a wasteful number, since it uses less digits than its factorization.

421818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541.

The product of its digits is 512, while the sum is 24.

The square root of 421818 is about 649.4751727356. The cubic root of 421818 is about 74.9966220701.

The spelling of 421818 in words is "four hundred twenty-one thousand, eight hundred eighteen".