1643841 has 16 divisors (see below), whose sum is σ = 2462400. Its totient is φ = 1083744.

The previous prime is 1643839. The next prime is 1643843. The reversal of 1643841 is 1483461.

It is an interprime number because it is at equal distance from previous prime (1643839) and next prime (1643843).

It is not a de Polignac number, because 1643841 - 2¹ = 1643839 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1643843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2605 + ... + 3173.

It is an arithmetic number, because the mean of its divisors is an integer number (153900).

2^1643841 is an apocalyptic number.

It is an amenable number.

1643841 is a deficient number, since it is larger than the sum of its proper divisors (818559).

1643841 is a wasteful number, since it uses less digits than its factorization.

1643841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685 (or 679 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 1643841 is about 1282.1236289844. The cubic root of 1643841 is about 118.0193638623.

It can be divided in two parts, 164 and 3841, that added together give a triangular number (4005 = T₈₉).

The spelling of 1643841 in words is "one million, six hundred forty-three thousand, eight hundred forty-one".