778640851 has 18 divisors (see below), whose sum is σ = 838477172. Its totient is φ = 722910720.

The previous prime is 778640809. The next prime is 778640893. The reversal of 778640851 is 158046877.

It is an interprime number because it is at equal distance from previous prime (778640809) and next prime (778640893).

It is not a de Polignac number, because 778640851 - 2²³ = 770252243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778640351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3690136 + ... + 3690346.

Almost surely, 2^778640851 is an apocalyptic number.

778640851 is a deficient number, since it is larger than the sum of its proper divisors (59836321).

778640851 is a wasteful number, since it uses less digits than its factorization.

778640851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471 (or 341 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 46.

The square root of 778640851 is about 27904.1368080075. The cubic root of 778640851 is about 919.9814311785.

The spelling of 778640851 in words is "seven hundred seventy-eight million, six hundred forty thousand, eight hundred fifty-one".