816855938 has 4 divisors (see below), whose sum is σ = 1225283910. Its totient is φ = 408427968.

The previous prime is 816855937. The next prime is 816855947. The reversal of 816855938 is 839558618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 839558618 = 2 ⋅419779309.

It can be written as a sum of positive squares in only one way, i.e., 813219289 + 3636649 = 28517^2 + 1907^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 816855938.

It is not an unprimeable number, because it can be changed into a prime (816855931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204213983 + ... + 204213986.

Almost surely, 2^816855938 is an apocalyptic number.

816855938 is a deficient number, since it is larger than the sum of its proper divisors (408427972).

816855938 is a wasteful number, since it uses less digits than its factorization.

816855938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408427971.

The product of its digits is 2073600, while the sum is 53.

The square root of 816855938 is about 28580.6916991174. The cubic root of 816855938 is about 934.7923654587.

The spelling of 816855938 in words is "eight hundred sixteen million, eight hundred fifty-five thousand, nine hundred thirty-eight".