331122221 has 4 divisors (see below), whose sum is σ = 331165500. Its totient is φ = 331078944.

The previous prime is 331122179. The next prime is 331122223. The reversal of 331122221 is 122221133.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122221133 = 547 ⋅223439.

It can be written as a sum of positive squares in 2 ways, for example, as 215796100 + 115326121 = 14690^2 + 10739^2 .

It is a cyclic number.

It is not a de Polignac number, because 331122221 - 2¹⁸ = 330860077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 331122221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331122223) 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, 6746 + ... + 26603.

It is an arithmetic number, because the mean of its divisors is an integer number (82791375).

Almost surely, 2^331122221 is an apocalyptic number.

It is an amenable number.

331122221 is a deficient number, since it is larger than the sum of its proper divisors (43279).

331122221 is an equidigital number, since it uses as much as digits as its factorization.

331122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43278.

The product of its digits is 144, while the sum is 17.

The square root of 331122221 is about 18196.7640255074. The cubic root of 331122221 is about 691.8247722821.

Adding to 331122221 its reverse (122221133), we get a palindrome (453343354).

The spelling of 331122221 in words is "three hundred thirty-one million, one hundred twenty-two thousand, two hundred twenty-one".