809640519 has 12 divisors (see below), whose sum is σ = 1086630696. Its totient is φ = 536210688.

The previous prime is 809640499. The next prime is 809640527. The reversal of 809640519 is 915046908.

It is not a de Polignac number, because 809640519 - 2¹¹ = 809638471 is a prime.

It is a super-2 number, since 2×809640519² = 1311035540013178722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809640569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 647607 + ... + 648855.

It is an arithmetic number, because the mean of its divisors is an integer number (90552558).

Almost surely, 2^809640519 is an apocalyptic number.

809640519 is a deficient number, since it is larger than the sum of its proper divisors (276990177).

809640519 is an equidigital number, since it uses as much as digits as its factorization.

809640519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2674 (or 1425 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 809640519 is about 28454.1828032365. The cubic root of 809640519 is about 932.0318312515.

The spelling of 809640519 in words is "eight hundred nine million, six hundred forty thousand, five hundred nineteen".