778706166671 has 4 divisors (see below), whose sum is σ = 778746208032. Its totient is φ = 778666125312.

The previous prime is 778706166647. The next prime is 778706166713. The reversal of 778706166671 is 176661607877.

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

It is a cyclic number.

It is not a de Polignac number, because 778706166671 - 2¹⁸ = 778705904527 is a prime.

It is a super-2 number, since 2×778706166671² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778706166611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19991495 + ... + 20030408.

It is an arithmetic number, because the mean of its divisors is an integer number (194686552008).

Almost surely, 2^778706166671 is an apocalyptic number.

778706166671 is a deficient number, since it is larger than the sum of its proper divisors (40041361).

778706166671 is a wasteful number, since it uses less digits than its factorization.

778706166671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40041360.

The product of its (nonzero) digits is 24893568, while the sum is 62.

The spelling of 778706166671 in words is "seven hundred seventy-eight billion, seven hundred six million, one hundred sixty-six thousand, six hundred seventy-one".