1020815 has 4 divisors (see below), whose sum is σ = 1224984. Its totient is φ = 816648.

The previous prime is 1020797. The next prime is 1020821. The reversal of 1020815 is 5180201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5180201 = 13 ⋅398477.

It is a cyclic number.

It is not a de Polignac number, because 1020815 - 2⁶ = 1020751 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020793 and 1020802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102077 + ... + 102086.

It is an arithmetic number, because the mean of its divisors is an integer number (306246).

2^1020815 is an apocalyptic number.

1020815 is a deficient number, since it is larger than the sum of its proper divisors (204169).

1020815 is an equidigital number, since it uses as much as digits as its factorization.

1020815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204168.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1020815 is about 1010.3538983940. The cubic root of 1020815 is about 100.6890741946.

The spelling of 1020815 in words is "one million, twenty thousand, eight hundred fifteen".