816769805 has 6 divisors (see below), whose sum is σ = 980200458. Its totient is φ = 653364720.

The previous prime is 816769801. The next prime is 816769819. The reversal of 816769805 is 508967618.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 237838084 + 578931721 = 15422^2 + 24061^2 .

It is not a de Polignac number, because 816769805 - 2² = 816769801 is a prime.

It is a super-2 number, since 2×816769805² = 1334225828719476050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816769801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 57515 + ... + 70295.

It is an arithmetic number, because the mean of its divisors is an integer number (163366743).

Almost surely, 2^816769805 is an apocalyptic number.

It is an amenable number.

816769805 is a deficient number, since it is larger than the sum of its proper divisors (163430653).

816769805 is an frugal number, since it uses more digits than its factorization.

816769805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25567 (or 12786 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 50.

The square root of 816769805 is about 28579.1848204248. The cubic root of 816769805 is about 934.7595080530.

The spelling of 816769805 in words is "eight hundred sixteen million, seven hundred sixty-nine thousand, eight hundred five".