778997 has 4 divisors (see below), whose sum is σ = 780780. Its totient is φ = 777216.

The previous prime is 778993. The next prime is 779003. The reversal of 778997 is 799877.

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

It can be written as a sum of positive squares in 2 ways, for example, as 96721 + 682276 = 311^2 + 826^2 .

It is a cyclic number.

It is not a de Polignac number, because 778997 - 2² = 778993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778993) 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 in 3 ways as a sum of consecutive naturals, for example, 263 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (195195).

2⁷⁷⁸⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

778997 is a deficient number, since it is larger than the sum of its proper divisors (1783).

778997 is a wasteful number, since it uses less digits than its factorization.

778997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1782.

The product of its digits is 222264, while the sum is 47.

The square root of 778997 is about 882.6080670377. The cubic root of 778997 is about 92.0121675778.

The spelling of 778997 in words is "seven hundred seventy-eight thousand, nine hundred ninety-seven".