819945 has 48 divisors (see below), whose sum is σ = 1722240. Its totient is φ = 352512.

The previous prime is 819943. The next prime is 819977. The reversal of 819945 is 549918.

It is not a de Polignac number, because 819945 - 2¹ = 819943 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (819943) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5917 + ... + 6053.

It is an arithmetic number, because the mean of its divisors is an integer number (35880).

2⁸¹⁹⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

819945 is an abundant number, since it is smaller than the sum of its proper divisors (902295).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

819945 is a wasteful number, since it uses less digits than its factorization.

819945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 171 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 819945 is about 905.5081446348. The cubic root of 819945 is about 93.5969235237.

It can be divided in two parts, 819 and 945, that added together give a square (1764 = 42²).

The spelling of 819945 in words is "eight hundred nineteen thousand, nine hundred forty-five".