1331521361 has 2 divisors, whose sum is σ = 1331521362. Its totient is φ = 1331521360.

The previous prime is 1331521357. The next prime is 1331521423. The reversal of 1331521361 is 1631251331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1074528400 + 256992961 = 32780^2 + 16031^2 .

It is a cyclic number.

It is not a de Polignac number, because 1331521361 - 2² = 1331521357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1331521361.

It is not a weakly prime, because it can be changed into another prime (1334521361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665760680 + 665760681.

It is an arithmetic number, because the mean of its divisors is an integer number (665760681).

Almost surely, 2^1331521361 is an apocalyptic number.

It is an amenable number.

1331521361 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331521361 is an equidigital number, since it uses as much as digits as its factorization.

1331521361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 26.

The square root of 1331521361 is about 36490.0172787024. The cubic root of 1331521361 is about 1100.1436068709.

Adding to 1331521361 its reverse (1631251331), we get a palindrome (2962772692).

The spelling of 1331521361 in words is "one billion, three hundred thirty-one million, five hundred twenty-one thousand, three hundred sixty-one".