191478087857 has 16 divisors (see below), whose sum is σ = 221100537600. Its totient is φ = 162430833600.

The previous prime is 191478087847. The next prime is 191478087859. The reversal of 191478087857 is 758780874191.

191478087857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-191478087857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191478087793 and 191478087802.

It is not an unprimeable number, because it can be changed into a prime (191478087859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52382 + ... + 621047.

It is an arithmetic number, because the mean of its divisors is an integer number (13818783600).

Almost surely, 2^191478087857 is an apocalyptic number.

It is an amenable number.

191478087857 is a deficient number, since it is larger than the sum of its proper divisors (29622449743).

191478087857 is a wasteful number, since it uses less digits than its factorization.

191478087857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 673856.

The product of its (nonzero) digits is 31610880, while the sum is 65.

The spelling of 191478087857 in words is "one hundred ninety-one billion, four hundred seventy-eight million, eighty-seven thousand, eight hundred fifty-seven".