1331213221 has 16 divisors (see below), whose sum is σ = 1468938240. Its totient is φ = 1198612800.

The previous prime is 1331213201. The next prime is 1331213227. The reversal of 1331213221 is 1223121331.

It is a cyclic number.

It is not a de Polignac number, because 1331213221 - 2¹¹ = 1331211173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331213227) 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 15 ways as a sum of consecutive naturals, for example, 642375 + ... + 644443.

It is an arithmetic number, because the mean of its divisors is an integer number (91808640).

Almost surely, 2^1331213221 is an apocalyptic number.

It is an amenable number.

1331213221 is a deficient number, since it is larger than the sum of its proper divisors (137725019).

1331213221 is a wasteful number, since it uses less digits than its factorization.

1331213221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3276.

The product of its digits is 216, while the sum is 19.

The square root of 1331213221 is about 36485.7947837237. The cubic root of 1331213221 is about 1100.0587354312.

Adding to 1331213221 its reverse (1223121331), we get a palindrome (2554334552).

The spelling of 1331213221 in words is "one billion, three hundred thirty-one million, two hundred thirteen thousand, two hundred twenty-one".