1843990421789 has 2 divisors, whose sum is σ = 1843990421790. Its totient is φ = 1843990421788.

The previous prime is 1843990421761. The next prime is 1843990421813. The reversal of 1843990421789 is 9871240993481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1375952460100 + 468037961689 = 1173010^2 + 684133^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1843990421789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1843990421729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 921995210894 + 921995210895.

It is an arithmetic number, because the mean of its divisors is an integer number (921995210895).

Almost surely, 2^{1843990421789} is an apocalyptic number.

It is an amenable number.

1843990421789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1843990421789 is an equidigital number, since it uses as much as digits as its factorization.

1843990421789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31352832, while the sum is 65.

The spelling of 1843990421789 in words is "one trillion, eight hundred forty-three billion, nine hundred ninety million, four hundred twenty-one thousand, seven hundred eighty-nine".