817872769 has 6 divisors (see below), whose sum is σ = 951403074. Its totient is φ = 701033760.

The previous prime is 817872751. The next prime is 817872791. The reversal of 817872769 is 967278718.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 777740544 + 40132225 = 27888^2 + 6335^2 .

It is not a de Polignac number, because 817872769 - 2¹¹ = 817870721 is a prime.

It is a super-2 number, since 2×817872769² = 1337831732543454722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (817872719) 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, 8345592 + ... + 8345689.

It is an arithmetic number, because the mean of its divisors is an integer number (158567179).

Almost surely, 2^817872769 is an apocalyptic number.

It is an amenable number.

817872769 is a deficient number, since it is larger than the sum of its proper divisors (133530305).

817872769 is a wasteful number, since it uses less digits than its factorization.

817872769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16691295 (or 16691288 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 55.

The square root of 817872769 is about 28598.4749418566. The cubic root of 817872769 is about 935.1800844660.

The spelling of 817872769 in words is "eight hundred seventeen million, eight hundred seventy-two thousand, seven hundred sixty-nine".