778556 has 12 divisors (see below), whose sum is σ = 1372560. Its totient is φ = 386400.

The previous prime is 778553. The next prime is 778559. The reversal of 778556 is 655877.

It is an interprime number because it is at equal distance from previous prime (778553) and next prime (778559).

It is a super-2 number, since 2×778556² = 1212298890272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778553) 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, 41 + ... + 1248.

It is an arithmetic number, because the mean of its divisors is an integer number (114380).

2⁷⁷⁸⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

778556 is a deficient number, since it is larger than the sum of its proper divisors (594004).

778556 is a wasteful number, since it uses less digits than its factorization.

778556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444 (or 1442 counting only the distinct ones).

The product of its digits is 58800, while the sum is 38.

The square root of 778556 is about 882.3582039059. The cubic root of 778556 is about 91.9948012185.

The spelling of 778556 in words is "seven hundred seventy-eight thousand, five hundred fifty-six".