1213643731 has 2 divisors, whose sum is σ = 1213643732. Its totient is φ = 1213643730.

The previous prime is 1213643713. The next prime is 1213643773. The reversal of 1213643731 is 1373463121.

Together with previous prime (1213643713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1213643731 - 2¹¹ = 1213641683 is a prime.

It is a super-2 number, since 2×1213643731² = 2945862211591200722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1213643693 and 1213643702.

It is not a weakly prime, because it can be changed into another prime (1213643531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606821865 + 606821866.

It is an arithmetic number, because the mean of its divisors is an integer number (606821866).

Almost surely, 2^1213643731 is an apocalyptic number.

1213643731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213643731 is an equidigital number, since it uses as much as digits as its factorization.

1213643731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 31.

The square root of 1213643731 is about 34837.3898419500. The cubic root of 1213643731 is about 1066.6707979115.

The spelling of 1213643731 in words is "one billion, two hundred thirteen million, six hundred forty-three thousand, seven hundred thirty-one".