91389186706 has 4 divisors (see below), whose sum is σ = 137083780062. Its totient is φ = 45694593352.

The previous prime is 91389186661. The next prime is 91389186739. The reversal of 91389186706 is 60768198319.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60768198319 = 55109 ⋅1102691.

It can be written as a sum of positive squares in only one way, i.e., 63508536081 + 27880650625 = 252009^2 + 166975^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22847296675 + ... + 22847296678.

Almost surely, 2^91389186706 is an apocalyptic number.

91389186706 is a deficient number, since it is larger than the sum of its proper divisors (45694593356).

91389186706 is a wasteful number, since it uses less digits than its factorization.

91389186706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45694593355.

The product of its (nonzero) digits is 3919104, while the sum is 58.

The spelling of 91389186706 in words is "ninety-one billion, three hundred eighty-nine million, one hundred eighty-six thousand, seven hundred six".