221401220 has 24 divisors (see below), whose sum is σ = 485158464. Its totient is φ = 84709856.

The previous prime is 221401199. The next prime is 221401261. The reversal of 221401220 is 22104122.

It is a junction number, because it is equal to n+sod(n) for n = 221401195 and 221401204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240194 + ... + 241113.

It is an arithmetic number, because the mean of its divisors is an integer number (20214936).

Almost surely, 2^221401220 is an apocalyptic number.

221401220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221401220 is an abundant number, since it is smaller than the sum of its proper divisors (263757244).

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

221401220 is a wasteful number, since it uses less digits than its factorization.

221401220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481339 (or 481337 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 221401220 is about 14879.5571170650. The cubic root of 221401220 is about 604.9600137496.

Adding to 221401220 its reverse (22104122), we get a palindrome (243505342).

The spelling of 221401220 in words is "two hundred twenty-one million, four hundred one thousand, two hundred twenty".