1606181 has 4 divisors (see below), whose sum is σ = 1610700. Its totient is φ = 1601664.

The previous prime is 1606153. The next prime is 1606201. The reversal of 1606181 is 1816061.

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: 1816061 = 13 ⋅139697.

It can be written as a sum of positive squares in 2 ways, for example, as 624100 + 982081 = 790^2 + 991^2 .

It is a cyclic number.

It is not a de Polignac number, because 1606181 - 2⁶ = 1606117 is a prime.

It is a super-2 number, since 2×1606181² = 5159634809522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1676 + ... + 2453.

It is an arithmetic number, because the mean of its divisors is an integer number (402675).

2^1606181 is an apocalyptic number.

It is an amenable number.

1606181 is a deficient number, since it is larger than the sum of its proper divisors (4519).

1606181 is an equidigital number, since it uses as much as digits as its factorization.

1606181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4518.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1606181 is about 1267.3519637417. The cubic root of 1606181 is about 117.1111272806. Note that the first 4 decimals are identical.

The spelling of 1606181 in words is "one million, six hundred six thousand, one hundred eighty-one".