1644945 has 8 divisors (see below), whose sum is σ = 2631936. Its totient is φ = 877296.

The previous prime is 1644943. The next prime is 1644947. The reversal of 1644945 is 5494461.

1644945 is an esthetic number in base 4, because in such base its adjacent digits differ by 1.

It is an interprime number because it is at equal distance from previous prime (1644943) and next prime (1644947).

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

It is not a de Polignac number, because 1644945 - 2¹ = 1644943 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

1644945 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1644943) 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, 54817 + ... + 54846.

It is an arithmetic number, because the mean of its divisors is an integer number (328992).

2^1644945 is an apocalyptic number.

1644945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1644945 is a deficient number, since it is larger than the sum of its proper divisors (986991).

1644945 is a wasteful number, since it uses less digits than its factorization.

1644945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109671.

The product of its digits is 17280, while the sum is 33.

The square root of 1644945 is about 1282.5540924265. The cubic root of 1644945 is about 118.0457784649.

The spelling of 1644945 in words is "one million, six hundred forty-four thousand, nine hundred forty-five".