1000645 has 16 divisors (see below), whose sum is σ = 1272960. Its totient is φ = 753984.

The previous prime is 1000639. The next prime is 1000651. The reversal of 1000645 is 5460001.

1000645 = T₁₅₆ + T₁₅₇ + ... + T₂₁₃.

1000645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1000639) and next prime (1000651).

It is a cyclic number.

It is not a de Polignac number, because 1000645 - 2⁹ = 1000133 is a prime.

1000645 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9664 + ... + 9766.

It is an arithmetic number, because the mean of its divisors is an integer number (79560).

2^1000645 is an apocalyptic number.

It is an amenable number.

1000645 is a deficient number, since it is larger than the sum of its proper divisors (272315).

1000645 is a wasteful number, since it uses less digits than its factorization.

1000645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1000645 is about 1000.3224480136. The cubic root of 1000645 is about 100.0214953792.

Adding to 1000645 its reverse (5460001), we get a palindrome (6460646).

The spelling of 1000645 in words is "one million, six hundred forty-five", and thus it is an aban number.