816869 has 2 divisors, whose sum is σ = 816870. Its totient is φ = 816868.

The previous prime is 816859. The next prime is 816883. The reversal of 816869 is 968618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 748225 + 68644 = 865^2 + 262^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816869 is a prime.

It is a super-2 number, since 2×816869² = 1334549926322, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408434 + 408435.

It is an arithmetic number, because the mean of its divisors is an integer number (408435).

2⁸¹⁶⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

816869 is a deficient number, since it is larger than the sum of its proper divisors (1).

816869 is an equidigital number, since it uses as much as digits as its factorization.

816869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 816869 is about 903.8080548435. The cubic root of 816869 is about 93.4797348056.

The spelling of 816869 in words is "eight hundred sixteen thousand, eight hundred sixty-nine".