8199954778 has 4 divisors (see below), whose sum is σ = 12299932170. Its totient is φ = 4099977388.

The previous prime is 8199954751. The next prime is 8199954799. The reversal of 8199954778 is 8774599918.

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., 6380335129 + 1819619649 = 79877^2 + 42657^2 .

It is a super-2 number, since 2×8199954778² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2049988693 + ... + 2049988696.

Almost surely, 2^8199954778 is an apocalyptic number.

8199954778 is a deficient number, since it is larger than the sum of its proper divisors (4099977392).

8199954778 is a wasteful number, since it uses less digits than its factorization.

8199954778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4099977391.

The product of its digits is 45722880, while the sum is 67.

The square root of 8199954778 is about 90553.6016843063. The cubic root of 8199954778 is about 2016.5259682395.

The spelling of 8199954778 in words is "eight billion, one hundred ninety-nine million, nine hundred fifty-four thousand, seven hundred seventy-eight".