86939218981 has 2 divisors, whose sum is σ = 86939218982. Its totient is φ = 86939218980.

The previous prime is 86939218939. The next prime is 86939218991. The reversal of 86939218981 is 18981293968.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60130396225 + 26808822756 = 245215^2 + 163734^2 .

It is a cyclic number.

It is not a de Polignac number, because 86939218981 - 2¹⁹ = 86938694693 is a prime.

It is a super-2 number, since 2×86939218981² (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 (86939218901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43469609490 + 43469609491.

It is an arithmetic number, because the mean of its divisors is an integer number (43469609491).

Almost surely, 2^86939218981 is an apocalyptic number.

It is an amenable number.

86939218981 is a deficient number, since it is larger than the sum of its proper divisors (1).

86939218981 is an equidigital number, since it uses as much as digits as its factorization.

86939218981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13436928, while the sum is 64.

The spelling of 86939218981 in words is "eighty-six billion, nine hundred thirty-nine million, two hundred eighteen thousand, nine hundred eighty-one".