8251666778 has 8 divisors (see below), whose sum is σ = 12611038068. Its totient is φ = 4047987424.

The previous prime is 8251666747. The next prime is 8251666793. The reversal of 8251666778 is 8776661528.

It can be written as a sum of positive squares in 2 ways, for example, as 8249543929 + 2122849 = 90827^2 + 1457^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38922851 + ... + 38923062.

Almost surely, 2^8251666778 is an apocalyptic number.

8251666778 is a deficient number, since it is larger than the sum of its proper divisors (4359371290).

8251666778 is a wasteful number, since it uses less digits than its factorization.

8251666778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77845968.

The product of its digits is 6773760, while the sum is 56.

The square root of 8251666778 is about 90838.6854704536. The cubic root of 8251666778 is about 2020.7560789250.

The spelling of 8251666778 in words is "eight billion, two hundred fifty-one million, six hundred sixty-six thousand, seven hundred seventy-eight".