1944781 has 2 divisors, whose sum is σ = 1944782. Its totient is φ = 1944780.

The previous prime is 1944779. The next prime is 1944791. The reversal of 1944781 is 1874491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1359556 + 585225 = 1166^2 + 765^2 .

It is an emirp because it is prime and its reverse (1874491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1944781 - 2¹ = 1944779 is a prime.

It is a super-2 number, since 2×1944781² = 7564346275922, which contains 22 as substring.

Together with 1944779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1944721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 972390 + 972391.

It is an arithmetic number, because the mean of its divisors is an integer number (972391).

2^1944781 is an apocalyptic number.

It is an amenable number.

1944781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1944781 is an equidigital number, since it uses as much as digits as its factorization.

1944781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 1944781 is about 1394.5540505839. The cubic root of 1944781 is about 124.8217405761.

The spelling of 1944781 in words is "one million, nine hundred forty-four thousand, seven hundred eighty-one".