809373645 has 18 divisors (see below), whose sum is σ = 1403245194. Its totient is φ = 431564160.

The previous prime is 809373641. The next prime is 809373671. The reversal of 809373645 is 546373908.

It can be written as a sum of positive squares in 3 ways, for example, as 561405636 + 247968009 = 23694^2 + 15747^2 .

It is not a de Polignac number, because 809373645 - 2² = 809373641 is a prime.

It is a super-3 number, since 3×809373645³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 809373645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809373641) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 188725 + ... + 192965.

Almost surely, 2^809373645 is an apocalyptic number.

It is an amenable number.

809373645 is a deficient number, since it is larger than the sum of its proper divisors (593871549).

809373645 is an frugal number, since it uses more digits than its factorization.

809373645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8493 (or 4249 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 809373645 is about 28449.4928777298. The cubic root of 809373645 is about 931.9294144416.

Multiplying 809373645 by its sum of digits (45), we get a square (36421814025 = 190845²).

809373645 divided by its sum of digits (45) gives a square (17986081 = 4241²).

It can be divided in two parts, 809373 and 645, that added together give a palindrome (810018).

The spelling of 809373645 in words is "eight hundred nine million, three hundred seventy-three thousand, six hundred forty-five".