1243686131 has 2 divisors, whose sum is σ = 1243686132. Its totient is φ = 1243686130.

The previous prime is 1243686127. The next prime is 1243686133. The reversal of 1243686131 is 1316863421.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1243686131 - 2² = 1243686127 is a prime.

It is a super-2 number, since 2×1243686131² = 3093510384883498322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1243686133, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1243686091 and 1243686100.

It is not a weakly prime, because it can be changed into another prime (1243686133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621843065 + 621843066.

It is an arithmetic number, because the mean of its divisors is an integer number (621843066).

Almost surely, 2^1243686131 is an apocalyptic number.

1243686131 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243686131 is an equidigital number, since it uses as much as digits as its factorization.

1243686131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 35.

The square root of 1243686131 is about 35265.9344268658. The cubic root of 1243686131 is about 1075.4005735583.

The spelling of 1243686131 in words is "one billion, two hundred forty-three million, six hundred eighty-six thousand, one hundred thirty-one".