816808501 has 4 divisors (see below), whose sum is σ = 823240192. Its totient is φ = 810376812.

The previous prime is 816808471. The next prime is 816808549. The reversal of 816808501 is 105808618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 816808501 - 2⁹ = 816807989 is a prime.

It is a super-2 number, since 2×816808501² = 1334352254611734002, 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 (816808901) 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, 3215655 + ... + 3215908.

It is an arithmetic number, because the mean of its divisors is an integer number (205810048).

Almost surely, 2^816808501 is an apocalyptic number.

It is an amenable number.

816808501 is a deficient number, since it is larger than the sum of its proper divisors (6431691).

816808501 is a wasteful number, since it uses less digits than its factorization.

816808501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6431690.

The product of its (nonzero) digits is 15360, while the sum is 37.

The square root of 816808501 is about 28579.8618086232. The cubic root of 816808501 is about 934.7742698143.

The spelling of 816808501 in words is "eight hundred sixteen million, eight hundred eight thousand, five hundred one".