221805420 has 48 divisors (see below), whose sum is σ = 629814528. Its totient is φ = 58313920.

The previous prime is 221805413. The next prime is 221805421. The reversal of 221805420 is 24508122.

It is not an unprimeable number, because it can be changed into a prime (221805421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21774 + ... + 30293.

It is an arithmetic number, because the mean of its divisors is an integer number (13121136).

Almost surely, 2^221805420 is an apocalyptic number.

221805420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221805420 is an abundant number, since it is smaller than the sum of its proper divisors (408009108).

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

221805420 is a wasteful number, since it uses less digits than its factorization.

221805420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52150 (or 52148 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 221805420 is about 14893.1333170693. The cubic root of 221805420 is about 605.3279373216.

The spelling of 221805420 in words is "two hundred twenty-one million, eight hundred five thousand, four hundred twenty".