805778899 has 2 divisors, whose sum is σ = 805778900. Its totient is φ = 805778898.

The previous prime is 805778887. The next prime is 805778959. The reversal of 805778899 is 998877508.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 805778899 - 2¹⁵ = 805746131 is a prime.

It is not a weakly prime, because it can be changed into another prime (805778839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402889449 + 402889450.

It is an arithmetic number, because the mean of its divisors is an integer number (402889450).

Almost surely, 2^805778899 is an apocalyptic number.

805778899 is a deficient number, since it is larger than the sum of its proper divisors (1).

805778899 is an equidigital number, since it uses as much as digits as its factorization.

805778899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10160640, while the sum is 61.

The square root of 805778899 is about 28386.2448907917. The cubic root of 805778899 is about 930.5476787180.

The spelling of 805778899 in words is "eight hundred five million, seven hundred seventy-eight thousand, eight hundred ninety-nine".