1331223121 has 2 divisors, whose sum is σ = 1331223122. Its totient is φ = 1331223120.

The previous prime is 1331223083. The next prime is 1331223143. The reversal of 1331223121 is 1213221331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 759774096 + 571449025 = 27564^2 + 23905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331223121 - 2⁹ = 1331222609 is a prime.

It is not a weakly prime, because it can be changed into another prime (1331223151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665611560 + 665611561.

It is an arithmetic number, because the mean of its divisors is an integer number (665611561).

Almost surely, 2^1331223121 is an apocalyptic number.

It is an amenable number.

1331223121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331223121 is an equidigital number, since it uses as much as digits as its factorization.

1331223121 is an evil number, because the sum of its binary digits is even.

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

The square root of 1331223121 is about 36485.9304527101. The cubic root of 1331223121 is about 1100.0614624059.

Adding to 1331223121 its reverse (1213221331), we get a palindrome (2544444452).

The spelling of 1331223121 in words is "one billion, three hundred thirty-one million, two hundred twenty-three thousand, one hundred twenty-one".