1020865 has 4 divisors (see below), whose sum is σ = 1225044. Its totient is φ = 816688.

The previous prime is 1020853. The next prime is 1020881. The reversal of 1020865 is 5680201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5680201 = 29 ⋅195869.

It can be written as a sum of positive squares in 2 ways, for example, as 106929 + 913936 = 327^2 + 956^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020865 - 2⁹ = 1020353 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 102082 + ... + 102091.

It is an arithmetic number, because the mean of its divisors is an integer number (306261).

2^1020865 is an apocalyptic number.

It is an amenable number.

1020865 is a deficient number, since it is larger than the sum of its proper divisors (204179).

1020865 is an equidigital number, since it uses as much as digits as its factorization.

1020865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204178.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 1020865 is about 1010.3786418962. The cubic root of 1020865 is about 100.6907181005.

The spelling of 1020865 in words is "one million, twenty thousand, eight hundred sixty-five".