221330421 has 32 divisors (see below), whose sum is σ = 364528640. Its totient is φ = 131803200.

The previous prime is 221330401. The next prime is 221330437. The reversal of 221330421 is 124033122.

221330421 is a `hidden beast` number, since 2 + 213 + 30 + 421 = 666.

It is not a de Polignac number, because 221330421 - 2²¹ = 219233269 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221330394 and 221330403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221330401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 711 + ... + 21051.

It is an arithmetic number, because the mean of its divisors is an integer number (11391520).

Almost surely, 2^221330421 is an apocalyptic number.

It is an amenable number.

221330421 is a deficient number, since it is larger than the sum of its proper divisors (143198219).

221330421 is a wasteful number, since it uses less digits than its factorization.

221330421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20394 (or 20388 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221330421 is about 14877.1778573760. The cubic root of 221330421 is about 604.8955227917.

Adding to 221330421 its reverse (124033122), we get a palindrome (345363543).

The spelling of 221330421 in words is "two hundred twenty-one million, three hundred thirty thousand, four hundred twenty-one".