221121331 has 4 divisors (see below), whose sum is σ = 221260032. Its totient is φ = 220982632.

The previous prime is 221121293. The next prime is 221121343. The reversal of 221121331 is 133121122.

221121331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221121331 - 2¹⁵ = 221088563 is a prime.

It is a super-2 number, since 2×221121331² = 97789286046423122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221121391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66931 + ... + 70156.

It is an arithmetic number, because the mean of its divisors is an integer number (55315008).

Almost surely, 2^221121331 is an apocalyptic number.

221121331 is a deficient number, since it is larger than the sum of its proper divisors (138701).

221121331 is a wasteful number, since it uses less digits than its factorization.

221121331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138700.

The product of its digits is 72, while the sum is 16.

The square root of 221121331 is about 14870.1489905112. The cubic root of 221121331 is about 604.7049819511.

Adding to 221121331 its reverse (133121122), we get a palindrome (354242453).

The spelling of 221121331 in words is "two hundred twenty-one million, one hundred twenty-one thousand, three hundred thirty-one".