778643481 has 16 divisors (see below), whose sum is σ = 1294368768. Its totient is φ = 404490000.

The previous prime is 778643471. The next prime is 778643483. The reversal of 778643481 is 184346877.

It is not a de Polignac number, because 778643481 - 2¹⁰ = 778642457 is a prime.

It is a super-2 number, since 2×778643481² = 1212571341007594722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 778643481.

It is not an unprimeable number, because it can be changed into a prime (778643483) 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 15 ways as a sum of consecutive naturals, for example, 1685145 + ... + 1685606.

It is an arithmetic number, because the mean of its divisors is an integer number (80898048).

Almost surely, 2^778643481 is an apocalyptic number.

It is an amenable number.

778643481 is a deficient number, since it is larger than the sum of its proper divisors (515725287).

778643481 is a wasteful number, since it uses less digits than its factorization.

778643481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3370772.

The product of its digits is 903168, while the sum is 48.

The square root of 778643481 is about 27904.1839335968. The cubic root of 778643481 is about 919.9824669784.

The spelling of 778643481 in words is "seven hundred seventy-eight million, six hundred forty-three thousand, four hundred eighty-one".