1944721 has 2 divisors, whose sum is σ = 1944722. Its totient is φ = 1944720.

The previous prime is 1944713. The next prime is 1944727. The reversal of 1944721 is 1274491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1535121 + 409600 = 1239^2 + 640^2 .

It is a cyclic number.

It is not a de Polignac number, because 1944721 - 2³ = 1944713 is a prime.

1944721 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1944721.

It is not a weakly prime, because it can be changed into another prime (1944727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 972360 + 972361.

It is an arithmetic number, because the mean of its divisors is an integer number (972361).

2^1944721 is an apocalyptic number.

It is an amenable number.

1944721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1944721 is an equidigital number, since it uses as much as digits as its factorization.

1944721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 28.

The square root of 1944721 is about 1394.5325381647. The cubic root of 1944721 is about 124.8204569044.

The spelling of 1944721 in words is "one million, nine hundred forty-four thousand, seven hundred twenty-one".