1311421531531 has 2 divisors, whose sum is σ = 1311421531532. Its totient is φ = 1311421531530.

The previous prime is 1311421531489. The next prime is 1311421531559. The reversal of 1311421531531 is 1351351241131.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1351351241131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1311421531531 - 2¹³ = 1311421523339 is a prime.

It is a super-2 number, since 2×1311421531531² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1311421531493 and 1311421531502.

It is not a weakly prime, because it can be changed into another prime (1311421511531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655710765765 + 655710765766.

It is an arithmetic number, because the mean of its divisors is an integer number (655710765766).

Almost surely, 2^{1311421531531} is an apocalyptic number.

1311421531531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311421531531 is an equidigital number, since it uses as much as digits as its factorization.

1311421531531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 31.

Adding to 1311421531531 its reverse (1351351241131), we get a palindrome (2662772772662).

The spelling of 1311421531531 in words is "one trillion, three hundred eleven billion, four hundred twenty-one million, five hundred thirty-one thousand, five hundred thirty-one".