1843981 has 2 divisors, whose sum is σ = 1843982. Its totient is φ = 1843980.

The previous prime is 1843967. The next prime is 1843993. The reversal of 1843981 is 1893481.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1121481 + 722500 = 1059^2 + 850^2 .

It is an emirp because it is prime and its reverse (1893481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1843981 - 2⁵ = 1843949 is a prime.

It is a super-2 number, since 2×1843981² = 6800531856722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1843901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 921990 + 921991.

It is an arithmetic number, because the mean of its divisors is an integer number (921991).

2^1843981 is an apocalyptic number.

It is an amenable number.

1843981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1843981 is an equidigital number, since it uses as much as digits as its factorization.

1843981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 34.

The square root of 1843981 is about 1357.9326198306. The cubic root of 1843981 is about 122.6268240891.

The spelling of 1843981 in words is "one million, eight hundred forty-three thousand, nine hundred eighty-one".