80777779 has 4 divisors (see below), whose sum is σ = 82656376. Its totient is φ = 78899184.

The previous prime is 80777773. The next prime is 80777821. The reversal of 80777779 is 97777708.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 80777779 - 2⁷ = 80777651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (80777773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 939234 + ... + 939319.

It is an arithmetic number, because the mean of its divisors is an integer number (20664094).

Almost surely, 2^80777779 is an apocalyptic number.

80777779 is a deficient number, since it is larger than the sum of its proper divisors (1878597).

80777779 is a wasteful number, since it uses less digits than its factorization.

80777779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1878596.

The product of its (nonzero) digits is 1210104, while the sum is 52.

The square root of 80777779 is about 8987.6459098031. The cubic root of 80777779 is about 432.2788319792.

The spelling of 80777779 in words is "eighty million, seven hundred seventy-seven thousand, seven hundred seventy-nine".