1644949 has 2 divisors, whose sum is σ = 1644950. Its totient is φ = 1644948.

The previous prime is 1644947. The next prime is 1644989. The reversal of 1644949 is 9494461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 964324 + 680625 = 982^2 + 825^2 .

It is an emirp because it is prime and its reverse (9494461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1644949 - 2¹ = 1644947 is a prime.

Together with 1644947, 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 (1644943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822474 + 822475.

It is an arithmetic number, because the mean of its divisors is an integer number (822475).

2^1644949 is an apocalyptic number.

It is an amenable number.

1644949 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644949 is an equidigital number, since it uses as much as digits as its factorization.

1644949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 1644949 is about 1282.5556518140. Note that the first 3 decimals coincide. The cubic root of 1644949 is about 118.0458741485.

The spelling of 1644949 in words is "one million, six hundred forty-four thousand, nine hundred forty-nine".