778643712 has 648 divisors, whose sum is σ = 3099112800. Its totient is φ = 191600640.

The previous prime is 778643681. The next prime is 778643717. The reversal of 778643712 is 217346877.

778643712 = T₁₃₃ + T₁₃₄ + ... + T₁₆₇₁.

It is a nude number because it is divisible by every one of its digits.

Its product of digits (395136) is a multiple of the sum of its prime divisors (42).

It is not an unprimeable number, because it can be changed into a prime (778643717) 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 71 ways as a sum of consecutive naturals, for example, 40981239 + ... + 40981257.

Almost surely, 2^778643712 is an apocalyptic number.

778643712 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 778643712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1549556400).

778643712 is an abundant number, since it is smaller than the sum of its proper divisors (2320469088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

778643712 is a wasteful number, since it uses less digits than its factorization.

778643712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80 (or 42 counting only the distinct ones).

The product of its digits is 395136, while the sum is 45.

The square root of 778643712 is about 27904.1880727607. The cubic root of 778643712 is about 919.9825579554.

The spelling of 778643712 in words is "seven hundred seventy-eight million, six hundred forty-three thousand, seven hundred twelve".