816545 has 4 divisors (see below), whose sum is σ = 979860. Its totient is φ = 653232.

The previous prime is 816539. The next prime is 816547. The reversal of 816545 is 545618.

It is a happy number.

816545 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 545618 = 2 ⋅272809.

It can be written as a sum of positive squares in 2 ways, for example, as 602176 + 214369 = 776^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 816545 - 2¹⁴ = 800161 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (816547) 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, 81650 + ... + 81659.

It is an arithmetic number, because the mean of its divisors is an integer number (244965).

2⁸¹⁶⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

816545 is a deficient number, since it is larger than the sum of its proper divisors (163315).

816545 is a wasteful number, since it uses less digits than its factorization.

816545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163314.

The product of its digits is 4800, while the sum is 29.

The square root of 816545 is about 903.6287954686. The cubic root of 816545 is about 93.4673740153.

The spelling of 816545 in words is "eight hundred sixteen thousand, five hundred forty-five".