221553321 has 16 divisors (see below), whose sum is σ = 326677440. Its totient is φ = 132433920.

The previous prime is 221553289. The next prime is 221553323. The reversal of 221553321 is 123355122.

It is a happy number.

It is not a de Polignac number, because 221553321 - 2⁵ = 221553289 is a prime.

It is a super-2 number, since 2×221553321² = 98171748092258082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221553291 and 221553300.

It is not an unprimeable number, because it can be changed into a prime (221553323) 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 15 ways as a sum of consecutive naturals, for example, 43576 + ... + 48393.

It is an arithmetic number, because the mean of its divisors is an integer number (20417340).

Almost surely, 2^221553321 is an apocalyptic number.

It is an amenable number.

221553321 is a deficient number, since it is larger than the sum of its proper divisors (105124119).

221553321 is a wasteful number, since it uses less digits than its factorization.

221553321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92056.

The product of its digits is 1800, while the sum is 24.

The square root of 221553321 is about 14884.6673123722. The cubic root of 221553321 is about 605.0985163888.

The spelling of 221553321 in words is "two hundred twenty-one million, five hundred fifty-three thousand, three hundred twenty-one".