78857681091 has 16 divisors (see below), whose sum is σ = 127232561664. Its totient is φ = 42410853504.

The previous prime is 78857681083. The next prime is 78857681093. The reversal of 78857681091 is 19018675887.

It is not a de Polignac number, because 78857681091 - 2³ = 78857681083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78857681093) 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, 110444575 + ... + 110445288.

It is an arithmetic number, because the mean of its divisors is an integer number (7952035104).

Almost surely, 2^78857681091 is an apocalyptic number.

78857681091 is a deficient number, since it is larger than the sum of its proper divisors (48374880573).

78857681091 is a wasteful number, since it uses less digits than its factorization.

78857681091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220889890.

The product of its (nonzero) digits is 6773760, while the sum is 60.

The spelling of 78857681091 in words is "seventy-eight billion, eight hundred fifty-seven million, six hundred eighty-one thousand, ninety-one".