8251516778 has 4 divisors (see below), whose sum is σ = 12377275170. Its totient is φ = 4125758388.

The previous prime is 8251516747. The next prime is 8251516811. The reversal of 8251516778 is 8776151528.

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

It can be written as a sum of positive squares in only one way, i.e., 8248817329 + 2699449 = 90823^2 + 1643^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2062879193 + ... + 2062879196.

Almost surely, 2^8251516778 is an apocalyptic number.

8251516778 is a deficient number, since it is larger than the sum of its proper divisors (4125758392).

8251516778 is a wasteful number, since it uses less digits than its factorization.

8251516778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4125758391.

The product of its digits is 940800, while the sum is 50.

The square root of 8251516778 is about 90837.8598272769. The cubic root of 8251516778 is about 2020.7438343181.

The spelling of 8251516778 in words is "eight billion, two hundred fifty-one million, five hundred sixteen thousand, seven hundred seventy-eight".