1644961 has 8 divisors (see below), whose sum is σ = 1719144. Its totient is φ = 1572480.

The previous prime is 1644949. The next prime is 1644989. The reversal of 1644961 is 1694461.

It can be written as a sum of positive squares in 4 ways, for example, as 129600 + 1515361 = 360^2 + 1231^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1644961 - 2¹⁹ = 1120673 is a prime.

It is a Duffinian number.

1644961 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1795 + ... + 2551.

It is an arithmetic number, because the mean of its divisors is an integer number (214893).

2^1644961 is an apocalyptic number.

It is an amenable number.

1644961 is a deficient number, since it is larger than the sum of its proper divisors (74183).

1644961 is an equidigital number, since it uses as much as digits as its factorization.

1644961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851.

The product of its digits is 5184, while the sum is 31.

The square root of 1644961 is about 1282.5603299650. The cubic root of 1644961 is about 118.0461611984.

It can be divided in two parts, 164 and 4961, that multiplied together give a square (813604 = 902²).

The spelling of 1644961 in words is "one million, six hundred forty-four thousand, nine hundred sixty-one".