645025 has 6 divisors (see below), whose sum is σ = 799862. Its totient is φ = 516000.

The previous prime is 645023. The next prime is 645037. The reversal of 645025 is 520546.

It can be written as a sum of positive squares in 3 ways, for example, as 42849 + 602176 = 207^2 + 776^2 .

It is not a de Polignac number, because 645025 - 2¹ = 645023 is a prime.

It is a Duffinian number.

645025 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 644987 and 645005.

It is not an unprimeable number, because it can be changed into a prime (645023) 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 5 ways as a sum of consecutive naturals, for example, 12876 + ... + 12925.

2⁶⁴⁵⁰²⁵ is an apocalyptic number.

It is an amenable number.

645025 is a deficient number, since it is larger than the sum of its proper divisors (154837).

645025 is a wasteful number, since it uses less digits than its factorization.

645025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25811 (or 25806 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 645025 is about 803.1344843798. The cubic root of 645025 is about 86.4023422576.

The spelling of 645025 in words is "six hundred forty-five thousand, twenty-five".