8155534865 has 16 divisors (see below), whose sum is σ = 10384854480. Its totient is φ = 6127288320.

The previous prime is 8155534859. The next prime is 8155534883. The reversal of 8155534865 is 5684355518.

It is a Cunningham number, because it is equal to 90308²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 833823376 + 7321711489 = 28876^2 + 85567^2 .

It is not a de Polignac number, because 8155534865 - 2⁸ = 8155534609 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64880 + ... + 143249.

It is an arithmetic number, because the mean of its divisors is an integer number (649053405).

Almost surely, 2^8155534865 is an apocalyptic number.

8155534865 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

8155534865 is a deficient number, since it is larger than the sum of its proper divisors (2229319615).

8155534865 is a wasteful number, since it uses less digits than its factorization.

8155534865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208612.

The product of its digits is 2880000, while the sum is 50.

The square root of 8155534865 is about 90308.0000055366. Note that the first 5 decimals coincide. The cubic root of 8155534865 is about 2012.8781375538.

The spelling of 8155534865 in words is "eight billion, one hundred fifty-five million, five hundred thirty-four thousand, eight hundred sixty-five".