80840909 has 2 divisors, whose sum is σ = 80840910. Its totient is φ = 80840908.

The previous prime is 80840873. The next prime is 80840911. The reversal of 80840909 is 90904808.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80048809 + 792100 = 8947^2 + 890^2 .

It is a cyclic number.

It is not a de Polignac number, because 80840909 - 2¹² = 80836813 is a prime.

Together with 80840911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80840939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40420454 + 40420455.

It is an arithmetic number, because the mean of its divisors is an integer number (40420455).

Almost surely, 2^80840909 is an apocalyptic number.

It is an amenable number.

80840909 is a deficient number, since it is larger than the sum of its proper divisors (1).

80840909 is an equidigital number, since it uses as much as digits as its factorization.

80840909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 80840909 is about 8991.1572670041. The cubic root of 80840909 is about 432.3914151543.

The spelling of 80840909 in words is "eighty million, eight hundred forty thousand, nine hundred nine".