8157205778 has 16 divisors (see below), whose sum is σ = 13027949280. Its totient is φ = 3817237056.

The previous prime is 8157205711. The next prime is 8157205781. The reversal of 8157205778 is 8775027518.

It is a super-2 number, since 2×8157205778² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 664076 + ... + 676247.

It is an arithmetic number, because the mean of its divisors is an integer number (814246830).

Almost surely, 2^8157205778 is an apocalyptic number.

8157205778 is a deficient number, since it is larger than the sum of its proper divisors (4870743502).

8157205778 is a wasteful number, since it uses less digits than its factorization.

8157205778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340521.

The product of its (nonzero) digits is 1097600, while the sum is 50.

The square root of 8157205778 is about 90317.2507221073. The cubic root of 8157205778 is about 2013.0155949017.

The spelling of 8157205778 in words is "eight billion, one hundred fifty-seven million, two hundred five thousand, seven hundred seventy-eight".