5111165681 has 4 divisors (see below), whose sum is σ = 5249305332. Its totient is φ = 4973026032.

The previous prime is 5111165671. The next prime is 5111165687. The reversal of 5111165681 is 1865611115.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4788640000 + 322525681 = 69200^2 + 17959^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5111165681 is a prime.

It is a super-2 number, since 2×5111165681² = 52248029237264387522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5111165687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69069770 + ... + 69069843.

It is an arithmetic number, because the mean of its divisors is an integer number (1312326333).

Almost surely, 2^5111165681 is an apocalyptic number.

It is an amenable number.

5111165681 is a deficient number, since it is larger than the sum of its proper divisors (138139651).

5111165681 is a wasteful number, since it uses less digits than its factorization.

5111165681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138139650.

The product of its digits is 7200, while the sum is 35.

The square root of 5111165681 is about 71492.4169475337. The cubic root of 5111165681 is about 1722.5558811584. Note that the first 3 decimals are identical.

Adding to 5111165681 its reverse (1865611115), we get a palindrome (6976776796).

The spelling of 5111165681 in words is "five billion, one hundred eleven million, one hundred sixty-five thousand, six hundred eighty-one".