76778673821 has 8 divisors (see below), whose sum is σ = 78656276664. Its totient is φ = 74901306880.

The previous prime is 76778673757. The next prime is 76778673847. The reversal of 76778673821 is 12837687767.

It can be written as a sum of positive squares in 4 ways, for example, as 22137273796 + 54641400025 = 148786^2 + 233755^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 76778673821 - 2⁶ = 76778673757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76778673721) 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 7 ways as a sum of consecutive naturals, for example, 726101 + ... + 825093.

It is an arithmetic number, because the mean of its divisors is an integer number (9832034583).

Almost surely, 2^76778673821 is an apocalyptic number.

It is an amenable number.

76778673821 is a deficient number, since it is larger than the sum of its proper divisors (1877602843).

76778673821 is a wasteful number, since it uses less digits than its factorization.

76778673821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117951.

The product of its digits is 33191424, while the sum is 62.

The spelling of 76778673821 in words is "seventy-six billion, seven hundred seventy-eight million, six hundred seventy-three thousand, eight hundred twenty-one".