1665025 has 6 divisors (see below), whose sum is σ = 2064662. Its totient is φ = 1332000.

The previous prime is 1665023. The next prime is 1665029. The reversal of 1665025 is 5205661.

It can be written as a sum of positive squares in 3 ways, for example, as 263169 + 1401856 = 513^2 + 1184^2 .

It is not a de Polignac number, because 1665025 - 2¹ = 1665023 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 66601 = 1665025 / (1 + 6 + 6 + 5 + 0 + 2 + 5).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665023) 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 5 ways as a sum of consecutive naturals, for example, 33276 + ... + 33325.

It is a Proth number, since it is equal to 813 ⋅ 2¹¹ + 1 and 813 < 2¹¹.

2^1665025 is an apocalyptic number.

It is an amenable number.

1665025 is a deficient number, since it is larger than the sum of its proper divisors (399637).

1665025 is an equidigital number, since it uses as much as digits as its factorization.

1665025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66611 (or 66606 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1665025 is about 1290.3584773233. The cubic root of 1665025 is about 118.5241691401.

It can be divided in two parts, 16 and 65025, that multiplied together give a square (1040400 = 1020²).

The spelling of 1665025 in words is "one million, six hundred sixty-five thousand, twenty-five".