8121580165 has 8 divisors (see below), whose sum is σ = 9749277720. Its totient is φ = 6495009792.

The previous prime is 8121580147. The next prime is 8121580171. The reversal of 8121580165 is 5610851218.

It can be written as a sum of positive squares in 4 ways, for example, as 39929761 + 8081650404 = 6319^2 + 89898^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 8121580165 - 2¹¹ = 8121578117 is a prime.

It is a congruent number.

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, 265860 + ... + 294829.

It is an arithmetic number, because the mean of its divisors is an integer number (1218659715).

Almost surely, 2^8121580165 is an apocalyptic number.

It is an amenable number.

8121580165 is a deficient number, since it is larger than the sum of its proper divisors (1627697555).

8121580165 is a wasteful number, since it uses less digits than its factorization.

8121580165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563591.

The product of its (nonzero) digits is 19200, while the sum is 37.

The square root of 8121580165 is about 90119.8100586103. The cubic root of 8121580165 is about 2010.0807839449.

The spelling of 8121580165 in words is "eight billion, one hundred twenty-one million, five hundred eighty thousand, one hundred sixty-five".