91130018618 has 4 divisors (see below), whose sum is σ = 136695027930. Its totient is φ = 45565009308.

The previous prime is 91130018599. The next prime is 91130018657. The reversal of 91130018618 is 81681003119.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81681003119 = 6869 ⋅11891251.

It can be written as a sum of positive squares in only one way, i.e., 52818611329 + 38311407289 = 229823^2 + 195733^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 22782504653 + ... + 22782504656.

Almost surely, 2^91130018618 is an apocalyptic number.

91130018618 is a deficient number, since it is larger than the sum of its proper divisors (45565009312).

91130018618 is a wasteful number, since it uses less digits than its factorization.

91130018618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45565009311.

The product of its (nonzero) digits is 10368, while the sum is 38.

The spelling of 91130018618 in words is "ninety-one billion, one hundred thirty million, eighteen thousand, six hundred eighteen".