778081 has 2 divisors, whose sum is σ = 778082. Its totient is φ = 778080.

The previous prime is 778079. The next prime is 778091. The reversal of 778081 is 180877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665856 + 112225 = 816^2 + 335^2 .

It is a cyclic number.

It is not a de Polignac number, because 778081 - 2¹ = 778079 is a prime.

It is a super-2 number, since 2×778081² = 1210820085122, which contains 22 as substring.

Together with 778079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (778051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389040 + 389041.

It is an arithmetic number, because the mean of its divisors is an integer number (389041).

2⁷⁷⁸⁰⁸¹ is an apocalyptic number.

It is an amenable number.

778081 is a deficient number, since it is larger than the sum of its proper divisors (1).

778081 is an equidigital number, since it uses as much as digits as its factorization.

778081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3136, while the sum is 31.

The square root of 778081 is about 882.0889977774. The cubic root of 778081 is about 91.9760886188.

The spelling of 778081 in words is "seven hundred seventy-eight thousand, eighty-one".