1606645 has 4 divisors (see below), whose sum is σ = 1927980. Its totient is φ = 1285312.

The previous prime is 1606643. The next prime is 1606663. The reversal of 1606645 is 5466061.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 904401 + 702244 = 951^2 + 838^2 .

It is a cyclic number.

It is not a de Polignac number, because 1606645 - 2¹ = 1606643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606643) 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 3 ways as a sum of consecutive naturals, for example, 160660 + ... + 160669.

It is an arithmetic number, because the mean of its divisors is an integer number (481995).

2^1606645 is an apocalyptic number.

It is an amenable number.

1606645 is a deficient number, since it is larger than the sum of its proper divisors (321335).

1606645 is an equidigital number, since it uses as much as digits as its factorization.

1606645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321334.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1606645 is about 1267.5350093784. The cubic root of 1606645 is about 117.1224033720.

The spelling of 1606645 in words is "one million, six hundred six thousand, six hundred forty-five".