8021121165 has 24 divisors (see below), whose sum is σ = 14382702360. Its totient is φ = 4130415744.

The previous prime is 8021121161. The next prime is 8021121167. The reversal of 8021121165 is 5611211208.

It can be written as a sum of positive squares in 4 ways, for example, as 423906921 + 7597214244 = 20589^2 + 87162^2 .

It is not a de Polignac number, because 8021121165 - 2² = 8021121161 is a prime.

It is a super-2 number, since 2×8021121165² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8021121161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3071922 + ... + 3074531.

It is an arithmetic number, because the mean of its divisors is an integer number (599279265).

Almost surely, 2^8021121165 is an apocalyptic number.

It is an amenable number.

8021121165 is a deficient number, since it is larger than the sum of its proper divisors (6361581195).

8021121165 is a wasteful number, since it uses less digits than its factorization.

8021121165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6146493 (or 6146490 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 8021121165 is about 89560.7121733632. The cubic root of 8021121165 is about 2001.7585503804.

The spelling of 8021121165 in words is "eight billion, twenty-one million, one hundred twenty-one thousand, one hundred sixty-five".