816138793 has 4 divisors (see below), whose sum is σ = 844281540. Its totient is φ = 787996048.

The previous prime is 816138779. The next prime is 816138797. The reversal of 816138793 is 397831618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 665020944 + 151117849 = 25788^2 + 12293^2 .

It is a cyclic number.

It is not a de Polignac number, because 816138793 - 2⁵ = 816138761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816138797) 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, 14071330 + ... + 14071387.

It is an arithmetic number, because the mean of its divisors is an integer number (211070385).

Almost surely, 2^816138793 is an apocalyptic number.

It is an amenable number.

816138793 is a deficient number, since it is larger than the sum of its proper divisors (28142747).

816138793 is a wasteful number, since it uses less digits than its factorization.

816138793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28142746.

The product of its digits is 217728, while the sum is 46.

The square root of 816138793 is about 28568.1429742992. The cubic root of 816138793 is about 934.5187235924.

The spelling of 816138793 in words is "eight hundred sixteen million, one hundred thirty-eight thousand, seven hundred ninety-three".