1028509309 has 2 divisors, whose sum is σ = 1028509310. Its totient is φ = 1028509308.

The previous prime is 1028509297. The next prime is 1028509343. The reversal of 1028509309 is 9039058201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 741037284 + 287472025 = 27222^2 + 16955^2 .

It is a cyclic number.

It is not a de Polignac number, because 1028509309 - 2²¹ = 1026412157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1028509369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 514254654 + 514254655.

It is an arithmetic number, because the mean of its divisors is an integer number (514254655).

Almost surely, 2^1028509309 is an apocalyptic number.

It is an amenable number.

1028509309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1028509309 is an equidigital number, since it uses as much as digits as its factorization.

1028509309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 1028509309 is about 32070.3805558961. The cubic root of 1028509309 is about 1009.4141977627.

The spelling of 1028509309 in words is "one billion, twenty-eight million, five hundred nine thousand, three hundred nine".