810799261 has 4 divisors (see below), whose sum is σ = 812605500. Its totient is φ = 808993024.

The previous prime is 810799259. The next prime is 810799267. The reversal of 810799261 is 162997018.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 162997018 = 2 ⋅81498509.

It can be written as a sum of positive squares in 2 ways, for example, as 648720900 + 162078361 = 25470^2 + 12731^2 .

It is a cyclic number.

It is not a de Polignac number, because 810799261 - 2¹ = 810799259 is a prime.

It is a super-2 number, since 2×810799261² = 1314790883276292242, 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 (810799267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 902446 + ... + 903343.

It is an arithmetic number, because the mean of its divisors is an integer number (203151375).

Almost surely, 2^810799261 is an apocalyptic number.

It is an amenable number.

810799261 is a deficient number, since it is larger than the sum of its proper divisors (1806239).

810799261 is a wasteful number, since it uses less digits than its factorization.

810799261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1806238.

The product of its (nonzero) digits is 54432, while the sum is 43.

The square root of 810799261 is about 28474.5370638400. The cubic root of 810799261 is about 932.4762546692.

The spelling of 810799261 in words is "eight hundred ten million, seven hundred ninety-nine thousand, two hundred sixty-one".