81491511135 has 16 divisors (see below), whose sum is σ = 130402746720. Its totient is φ = 43456696320.

The previous prime is 81491511053. The next prime is 81491511149. The reversal of 81491511135 is 53111519418.

It is not a de Polignac number, because 81491511135 - 2²⁹ = 80954640223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81491511093 and 81491511102.

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, 214930 + ... + 457359.

It is an arithmetic number, because the mean of its divisors is an integer number (8150171670).

Almost surely, 2^81491511135 is an apocalyptic number.

81491511135 is a deficient number, since it is larger than the sum of its proper divisors (48911235585).

81491511135 is a wasteful number, since it uses less digits than its factorization.

81491511135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680378.

The product of its digits is 21600, while the sum is 39.

The spelling of 81491511135 in words is "eighty-one billion, four hundred ninety-one million, five hundred eleven thousand, one hundred thirty-five".