1643161 has 4 divisors (see below), whose sum is σ = 1769572. Its totient is φ = 1516752.

The previous prime is 1643141. The next prime is 1643171. The reversal of 1643161 is 1613461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1613461 = 19 ⋅84919.

It can be written as a sum of positive squares in 2 ways, for example, as 309136 + 1334025 = 556^2 + 1155^2 .

It is a cyclic number.

It is not a de Polignac number, because 1643161 - 2⁵ = 1643129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63186 + ... + 63211.

It is an arithmetic number, because the mean of its divisors is an integer number (442393).

2^1643161 is an apocalyptic number.

It is an amenable number.

1643161 is a deficient number, since it is larger than the sum of its proper divisors (126411).

1643161 is a wasteful number, since it uses less digits than its factorization.

1643161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126410.

The product of its digits is 432, while the sum is 22.

The square root of 1643161 is about 1281.8584165188. The cubic root of 1643161 is about 118.0030881122.

The spelling of 1643161 in words is "one million, six hundred forty-three thousand, one hundred sixty-one".