1661841 has 6 divisors (see below), whose sum is σ = 2400450. Its totient is φ = 1107888.

The previous prime is 1661839. The next prime is 1661851. The reversal of 1661841 is 1481661.

1661841 is a `hidden beast` number, since 1 + 6 + 618 + 41 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1440000 + 221841 = 1200^2 + 471^2 .

It is not a de Polignac number, because 1661841 - 2¹ = 1661839 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661831) 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 in 5 ways as a sum of consecutive naturals, for example, 92316 + ... + 92333.

It is an arithmetic number, because the mean of its divisors is an integer number (400075).

2^1661841 is an apocalyptic number.

It is an amenable number.

1661841 is a deficient number, since it is larger than the sum of its proper divisors (738609).

1661841 is a wasteful number, since it uses less digits than its factorization.

1661841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184655 (or 184652 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 1661841 is about 1289.1241212544. The cubic root of 1661841 is about 118.4485703225.

The spelling of 1661841 in words is "one million, six hundred sixty-one thousand, eight hundred forty-one".