1645265 has 4 divisors (see below), whose sum is σ = 1974324. Its totient is φ = 1316208.

The previous prime is 1645253. The next prime is 1645291. The reversal of 1645265 is 5625461.

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 966289 + 678976 = 983^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645265 - 2⁴ = 1645249 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164522 + ... + 164531.

It is an arithmetic number, because the mean of its divisors is an integer number (493581).

2^1645265 is an apocalyptic number.

It is an amenable number.

1645265 is a deficient number, since it is larger than the sum of its proper divisors (329059).

1645265 is an equidigital number, since it uses as much as digits as its factorization.

1645265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329058.

The product of its digits is 7200, while the sum is 29.

The square root of 1645265 is about 1282.6788374336. The cubic root of 1645265 is about 118.0534326621.

The spelling of 1645265 in words is "one million, six hundred forty-five thousand, two hundred sixty-five".