1643431373 has 2 divisors, whose sum is σ = 1643431374. Its totient is φ = 1643431372.

The previous prime is 1643431337. The next prime is 1643431379. The reversal of 1643431373 is 3731343461.

Together with previous prime (1643431337) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1359913129 + 283518244 = 36877^2 + 16838^2 .

It is an emirp because it is prime and its reverse (3731343461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1643431373 - 2¹⁴ = 1643414989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1643431379) 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, 821715686 + 821715687.

It is an arithmetic number, because the mean of its divisors is an integer number (821715687).

Almost surely, 2^1643431373 is an apocalyptic number.

It is an amenable number.

1643431373 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643431373 is an equidigital number, since it uses as much as digits as its factorization.

1643431373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 35.

The square root of 1643431373 is about 40539.2571836239. The cubic root of 1643431373 is about 1180.0956000780.

The spelling of 1643431373 in words is "one billion, six hundred forty-three million, four hundred thirty-one thousand, three hundred seventy-three".