1028509865 has 8 divisors (see below), whose sum is σ = 1238233920. Its totient is φ = 820126512.

The previous prime is 1028509861. The next prime is 1028509871. The reversal of 1028509865 is 5689058201.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1028509865 - 2² = 1028509861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1028509861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333485 + ... + 336554.

It is an arithmetic number, because the mean of its divisors is an integer number (154779240).

Almost surely, 2^1028509865 is an apocalyptic number.

It is an amenable number.

1028509865 is a deficient number, since it is larger than the sum of its proper divisors (209724055).

1028509865 is an equidigital number, since it uses as much as digits as its factorization.

1028509865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670351.

The product of its (nonzero) digits is 172800, while the sum is 44.

The square root of 1028509865 is about 32070.3892243297. The cubic root of 1028509865 is about 1009.4143796552.

The spelling of 1028509865 in words is "one billion, twenty-eight million, five hundred nine thousand, eight hundred sixty-five".