81586778135 has 8 divisors (see below), whose sum is σ = 98062302480. Its totient is φ = 65163976704.

The previous prime is 81586778111. The next prime is 81586778153. The reversal of 81586778135 is 53187768518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81586778135 - 2³⁰ = 80513036311 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13177322 + ... + 13183511.

It is an arithmetic number, because the mean of its divisors is an integer number (12257787810).

Almost surely, 2^81586778135 is an apocalyptic number.

81586778135 is a deficient number, since it is larger than the sum of its proper divisors (16475524345).

81586778135 is a wasteful number, since it uses less digits than its factorization.

81586778135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26361457.

The product of its digits is 11289600, while the sum is 59.

The spelling of 81586778135 in words is "eighty-one billion, five hundred eighty-six million, seven hundred seventy-eight thousand, one hundred thirty-five".