1291923443 has 2 divisors, whose sum is σ = 1291923444. Its totient is φ = 1291923442.

The previous prime is 1291923401. The next prime is 1291923461. The reversal of 1291923443 is 3443291921.

It is a strong prime.

It is an emirp because it is prime and its reverse (3443291921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1291923443 - 2¹⁸ = 1291661299 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1291923397 and 1291923406.

It is not a weakly prime, because it can be changed into another prime (1291913443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645961721 + 645961722.

It is an arithmetic number, because the mean of its divisors is an integer number (645961722).

Almost surely, 2^1291923443 is an apocalyptic number.

1291923443 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291923443 is an equidigital number, since it uses as much as digits as its factorization.

1291923443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 38.

The square root of 1291923443 is about 35943.3365590898. The cubic root of 1291923443 is about 1089.1280075331.

The spelling of 1291923443 in words is "one billion, two hundred ninety-one million, nine hundred twenty-three thousand, four hundred forty-three".