809881791428 has 12 divisors (see below), whose sum is σ = 1417676109612. Its totient is φ = 404831474400.

The previous prime is 809881791427. The next prime is 809881791437. The reversal of 809881791428 is 824197188908.

It can be written as a sum of positive squares in 2 ways, for example, as 645631534144 + 164250257284 = 803512^2 + 405278^2 .

It is not an unprimeable number, because it can be changed into a prime (809881791427) 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, 27338675 + ... + 27368282.

It is an arithmetic number, because the mean of its divisors is an integer number (118139675801).

Almost surely, 2^809881791428 is an apocalyptic number.

It is an amenable number.

809881791428 is a deficient number, since it is larger than the sum of its proper divisors (607794318184).

809881791428 is a wasteful number, since it uses less digits than its factorization.

809881791428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54710662 (or 54710660 counting only the distinct ones).

The product of its (nonzero) digits is 18579456, while the sum is 65.

The spelling of 809881791428 in words is "eight hundred nine billion, eight hundred eighty-one million, seven hundred ninety-one thousand, four hundred twenty-eight".