221321331 has 48 divisors (see below), whose sum is σ = 405400320. Its totient is φ = 113002560.

The previous prime is 221321323. The next prime is 221321333. The reversal of 221321331 is 133123122.

It is not a de Polignac number, because 221321331 - 2³ = 221321323 is a prime.

It is a super-2 number, since 2×221321331² = 97966263111223122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221321333) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 38181 + ... + 43593.

It is an arithmetic number, because the mean of its divisors is an integer number (8445840).

Almost surely, 2^221321331 is an apocalyptic number.

221321331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221321331 is a deficient number, since it is larger than the sum of its proper divisors (184078989).

221321331 is a wasteful number, since it uses less digits than its factorization.

221321331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5496 (or 5493 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 221321331 is about 14876.8723527494. The cubic root of 221321331 is about 604.8872416955.

Adding to 221321331 its reverse (133123122), we get a palindrome (354444453).

The spelling of 221321331 in words is "two hundred twenty-one million, three hundred twenty-one thousand, three hundred thirty-one".