1809025 has 9 divisors (see below), whose sum is σ = 2251561. Its totient is φ = 1441840.

The previous prime is 1808993. The next prime is 1809029. The reversal of 1809025 is 5209081.

The square root of 1809025 is 1345.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 693889 + 1115136 = 833^2 + 1056^2 .

It is not a de Polignac number, because 1809025 - 2⁵ = 1808993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1809029) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6591 + ... + 6859.

2^1809025 is an apocalyptic number.

1809025 is the 1345-th square number.

1809025 is the 673-rd centered octagonal number.

It is an amenable number.

1809025 is a deficient number, since it is larger than the sum of its proper divisors (442536).

1809025 is an frugal number, since it uses more digits than its factorization.

1809025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The cubic root of 1809025 is about 121.8470043082.

Multiplying 1809025 by its sum of digits (25), we get a square (45225625 = 6725²).

1809025 divided by its sum of digits (25) gives a square (72361 = 269²).

The spelling of 1809025 in words is "one million, eight hundred nine thousand, twenty-five".