86181617981 has 2 divisors, whose sum is σ = 86181617982. Its totient is φ = 86181617980.

The previous prime is 86181617969. The next prime is 86181617993. The reversal of 86181617981 is 18971618168.

It is a balanced prime because it is at equal distance from previous prime (86181617969) and next prime (86181617993).

It can be written as a sum of positive squares in only one way, i.e., 84744449881 + 1437168100 = 291109^2 + 37910^2 .

It is a cyclic number.

It is not a de Polignac number, because 86181617981 - 2¹⁰ = 86181616957 is a prime.

It is a super-2 number, since 2×86181617981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86181017981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43090808990 + 43090808991.

It is an arithmetic number, because the mean of its divisors is an integer number (43090808991).

Almost surely, 2^86181617981 is an apocalyptic number.

It is an amenable number.

86181617981 is a deficient number, since it is larger than the sum of its proper divisors (1).

86181617981 is an equidigital number, since it uses as much as digits as its factorization.

86181617981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1161216, while the sum is 56.

The spelling of 86181617981 in words is "eighty-six billion, one hundred eighty-one million, six hundred seventeen thousand, nine hundred eighty-one".