215531313131 has 2 divisors, whose sum is σ = 215531313132. Its totient is φ = 215531313130.

The previous prime is 215531313119. The next prime is 215531313139. The reversal of 215531313131 is 131313135512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215531313131 - 2¹⁰ = 215531312107 is a prime.

It is a super-2 number, since 2×215531313131² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 215531313094 and 215531313103.

It is not a weakly prime, because it can be changed into another prime (215531313139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107765656565 + 107765656566.

It is an arithmetic number, because the mean of its divisors is an integer number (107765656566).

Almost surely, 2^215531313131 is an apocalyptic number.

215531313131 is a deficient number, since it is larger than the sum of its proper divisors (1).

215531313131 is an equidigital number, since it uses as much as digits as its factorization.

215531313131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4050, while the sum is 29.

Adding to 215531313131 its reverse (131313135512), we get a palindrome (346844448643).

The spelling of 215531313131 in words is "two hundred fifteen billion, five hundred thirty-one million, three hundred thirteen thousand, one hundred thirty-one".