81985099058918 has 32 divisors (see below), whose sum is σ = 138792854453760. Its totient is φ = 35978509798560.

The previous prime is 81985099058881. The next prime is 81985099058953.

It is a happy number.

81985099058918 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (80) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5237555 + ... + 13834817.

It is an arithmetic number, because the mean of its divisors is an integer number (4337276701680).

Almost surely, 2^{81985099058918} is an apocalyptic number.

81985099058918 is a deficient number, since it is larger than the sum of its proper divisors (56807755394842).

81985099058918 is a wasteful number, since it uses less digits than its factorization.

81985099058918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8612252.

The product of its (nonzero) digits is 671846400, while the sum is 80.

The spelling of 81985099058918 in words is "eighty-one trillion, nine hundred eighty-five billion, ninety-nine million, fifty-eight thousand, nine hundred eighteen".