8691538081 has 2 divisors, whose sum is σ = 8691538082. Its totient is φ = 8691538080.

The previous prime is 8691538043. The next prime is 8691538109. The reversal of 8691538081 is 1808351968.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7883841681 + 807696400 = 88791^2 + 28420^2 .

It is a cyclic number.

It is not a de Polignac number, because 8691538081 - 2¹⁷ = 8691407009 is a prime.

It is a super-2 number, since 2×8691538081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8691538181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4345769040 + 4345769041.

It is an arithmetic number, because the mean of its divisors is an integer number (4345769041).

Almost surely, 2^8691538081 is an apocalyptic number.

It is an amenable number.

8691538081 is a deficient number, since it is larger than the sum of its proper divisors (1).

8691538081 is an equidigital number, since it uses as much as digits as its factorization.

8691538081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 49.

The square root of 8691538081 is about 93228.4188485464. The cubic root of 8691538081 is about 2056.0430909207.

The spelling of 8691538081 in words is "eight billion, six hundred ninety-one million, five hundred thirty-eight thousand, eighty-one".