818945 has 4 divisors (see below), whose sum is σ = 982740. Its totient is φ = 655152.

The previous prime is 818897. The next prime is 818947. The reversal of 818945 is 549818.

818945 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: 549818 = 2 ⋅274909.

It can be written as a sum of positive squares in 2 ways, for example, as 190096 + 628849 = 436^2 + 793^2 .

It is a cyclic number.

It is not a de Polignac number, because 818945 - 2⁸ = 818689 is a prime.

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

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (818947) 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, 81890 + ... + 81899.

It is an arithmetic number, because the mean of its divisors is an integer number (245685).

2⁸¹⁸⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

818945 is a deficient number, since it is larger than the sum of its proper divisors (163795).

818945 is a wasteful number, since it uses less digits than its factorization.

818945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163794.

The product of its digits is 11520, while the sum is 35.

The square root of 818945 is about 904.9558000256. The cubic root of 818945 is about 93.5588579626.

The spelling of 818945 in words is "eight hundred eighteen thousand, nine hundred forty-five".