1605945 has 16 divisors (see below), whose sum is σ = 2803392. Its totient is φ = 778560.

The previous prime is 1605941. The next prime is 1605971. The reversal of 1605945 is 5495061.

It is not a de Polignac number, because 1605945 - 2² = 1605941 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1605941) 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, 4702 + ... + 5031.

It is an arithmetic number, because the mean of its divisors is an integer number (175212).

2^1605945 is an apocalyptic number.

1605945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1605945 is a deficient number, since it is larger than the sum of its proper divisors (1197447).

1605945 is a wasteful number, since it uses less digits than its factorization.

1605945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9752.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1605945 is about 1267.2588528000. The cubic root of 1605945 is about 117.1053911940.

It can be divided in two parts, 160 and 5945, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 1605945 in words is "one million, six hundred five thousand, nine hundred forty-five".