8121641765 has 16 divisors (see below), whose sum is σ = 9777823680. Its totient is φ = 6476112000.

The previous prime is 8121641753. The next prime is 8121641771. The reversal of 8121641765 is 5671461218.

It is not a de Polignac number, because 8121641765 - 2¹² = 8121637669 is a prime.

It is a super-2 number, since 2×8121641765² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 3606890 + ... + 3609140.

It is an arithmetic number, because the mean of its divisors is an integer number (611113980).

Almost surely, 2^8121641765 is an apocalyptic number.

It is an amenable number.

8121641765 is a deficient number, since it is larger than the sum of its proper divisors (1656181915).

8121641765 is a wasteful number, since it uses less digits than its factorization.

8121641765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4292.

The product of its digits is 80640, while the sum is 41.

The square root of 8121641765 is about 90120.1518252161. The cubic root of 8121641765 is about 2010.0858659060.

The spelling of 8121641765 in words is "eight billion, one hundred twenty-one million, six hundred forty-one thousand, seven hundred sixty-five".