81935514989569 has 16 divisors (see below), whose sum is σ = 87622587858816. Its totient is φ = 76344958816000.

The previous prime is 81935514989557. The next prime is 81935514989579. The reversal of 81935514989569 is 96598941553918.

It is a cyclic number.

It is not a de Polignac number, because 81935514989569 - 2¹⁹ = 81935514465281 is a prime.

It is a super-2 number, since 2×81935514989569² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81935514989492 and 81935514989501.

It is not an unprimeable number, because it can be changed into a prime (81935514989519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15730974 + ... + 20281384.

It is an arithmetic number, because the mean of its divisors is an integer number (5476411741176).

Almost surely, 2^{81935514989569} is an apocalyptic number.

It is an amenable number.

81935514989569 is a deficient number, since it is larger than the sum of its proper divisors (5687072869247).

81935514989569 is a wasteful number, since it uses less digits than its factorization.

81935514989569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4561016.

The product of its digits is 3779136000, while the sum is 82.

The spelling of 81935514989569 in words is "eighty-one trillion, nine hundred thirty-five billion, five hundred fourteen million, nine hundred eighty-nine thousand, five hundred sixty-nine".