123205215131 has 2 divisors, whose sum is σ = 123205215132. Its totient is φ = 123205215130.

The previous prime is 123205215121. The next prime is 123205215137. The reversal of 123205215131 is 131512502321.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123205215131 is a prime.

It is a super-2 number, since 2×123205215131² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123205215131.

It is not a weakly prime, because it can be changed into another prime (123205215137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61602607565 + 61602607566.

It is an arithmetic number, because the mean of its divisors is an integer number (61602607566).

Almost surely, 2^123205215131 is an apocalyptic number.

123205215131 is a deficient number, since it is larger than the sum of its proper divisors (1).

123205215131 is an equidigital number, since it uses as much as digits as its factorization.

123205215131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

Adding to 123205215131 its reverse (131512502321), we get a palindrome (254717717452).

The spelling of 123205215131 in words is "one hundred twenty-three billion, two hundred five million, two hundred fifteen thousand, one hundred thirty-one".