816538 has 8 divisors (see below), whose sum is σ = 1235988. Its totient is φ = 404544.

The previous prime is 816521. The next prime is 816539. The reversal of 816538 is 835618.

It can be written as a sum of positive squares in 2 ways, for example, as 471969 + 344569 = 687^2 + 587^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (816539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1581 + ... + 2032.

2⁸¹⁶⁵³⁸ is an apocalyptic number.

816538 is a deficient number, since it is larger than the sum of its proper divisors (419450).

816538 is a wasteful number, since it uses less digits than its factorization.

816538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3728.

The product of its digits is 5760, while the sum is 31.

The square root of 816538 is about 903.6249221884. The cubic root of 816538 is about 93.4671069251.

The spelling of 816538 in words is "eight hundred sixteen thousand, five hundred thirty-eight".