80909809 has 4 divisors (see below), whose sum is σ = 85168240. Its totient is φ = 76651380.

The previous prime is 80909779. The next prime is 80909813. The reversal of 80909809 is 90890908.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80909809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80909819) 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, 2129187 + ... + 2129224.

It is an arithmetic number, because the mean of its divisors is an integer number (21292060).

Almost surely, 2^80909809 is an apocalyptic number.

It is an amenable number.

80909809 is a deficient number, since it is larger than the sum of its proper divisors (4258431).

80909809 is a wasteful number, since it uses less digits than its factorization.

80909809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4258430.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 80909809 is about 8994.9879933216. The cubic root of 80909809 is about 432.5142214130.

It can be divided in two parts, 80909 and 809, that added together give a palindrome (81718).

The spelling of 80909809 in words is "eighty million, nine hundred nine thousand, eight hundred nine".