816555 has 8 divisors (see below), whose sum is σ = 1306512. Its totient is φ = 435488.

The previous prime is 816547. The next prime is 816559. The reversal of 816555 is 555618.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 816555 - 2³ = 816547 is a prime.

It is a super-3 number, since 3×816555³ = 1633343701368461625, which contains 333 as substring.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (816559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27204 + ... + 27233.

It is an arithmetic number, because the mean of its divisors is an integer number (163314).

2⁸¹⁶⁵⁵⁵ is an apocalyptic number.

816555 is a deficient number, since it is larger than the sum of its proper divisors (489957).

816555 is a wasteful number, since it uses less digits than its factorization.

816555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54445.

The product of its digits is 6000, while the sum is 30.

The square root of 816555 is about 903.6343286972. The cubic root of 816555 is about 93.4677555700.

The spelling of 816555 in words is "eight hundred sixteen thousand, five hundred fifty-five".