1331515121 has 2 divisors, whose sum is σ = 1331515122. Its totient is φ = 1331515120.

The previous prime is 1331515111. The next prime is 1331515153. The reversal of 1331515121 is 1215151331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1005207025 + 326308096 = 31705^2 + 18064^2 .

It is an emirp because it is prime and its reverse (1215151331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1331515121 - 2¹⁴ = 1331498737 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1331515111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665757560 + 665757561.

It is an arithmetic number, because the mean of its divisors is an integer number (665757561).

Almost surely, 2^1331515121 is an apocalyptic number.

It is an amenable number.

1331515121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331515121 is an equidigital number, since it uses as much as digits as its factorization.

1331515121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 450, while the sum is 23.

The square root of 1331515121 is about 36489.9317757652. The cubic root of 1331515121 is about 1100.1418883087.

Adding to 1331515121 its reverse (1215151331), we get a palindrome (2546666452).

The spelling of 1331515121 in words is "one billion, three hundred thirty-one million, five hundred fifteen thousand, one hundred twenty-one".