816298561 has 12 divisors (see below), whose sum is σ = 905487660. Its totient is φ = 735121920.

The previous prime is 816298559. The next prime is 816298591. The reversal of 816298561 is 165892618.

It can be written as a sum of positive squares in 6 ways, for example, as 134096400 + 682202161 = 11580^2 + 26119^2 .

It is not a de Polignac number, because 816298561 - 2¹ = 816298559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816298591) 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, 51976 + ... + 65833.

It is an arithmetic number, because the mean of its divisors is an integer number (75457305).

Almost surely, 2^816298561 is an apocalyptic number.

It is an amenable number.

816298561 is a deficient number, since it is larger than the sum of its proper divisors (89189099).

816298561 is a wasteful number, since it uses less digits than its factorization.

816298561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117876 (or 117863 counting only the distinct ones).

The product of its digits is 207360, while the sum is 46.

The square root of 816298561 is about 28570.9390990216. The cubic root of 816298561 is about 934.5797003311.

The spelling of 816298561 in words is "eight hundred sixteen million, two hundred ninety-eight thousand, five hundred sixty-one".