91861768618 has 8 divisors (see below), whose sum is σ = 138492108612. Its totient is φ = 45697732416.

The previous prime is 91861768573. The next prime is 91861768627. The reversal of 91861768618 is 81686716819.

It can be written as a sum of positive squares in 2 ways, for example, as 79646435089 + 12215333529 = 282217^2 + 110523^2 .

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

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 116575455 + ... + 116576242.

Almost surely, 2^91861768618 is an apocalyptic number.

91861768618 is a deficient number, since it is larger than the sum of its proper divisors (46630339994).

91861768618 is a wasteful number, since it uses less digits than its factorization.

91861768618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233151896.

The product of its digits is 6967296, while the sum is 61.

The spelling of 91861768618 in words is "ninety-one billion, eight hundred sixty-one million, seven hundred sixty-eight thousand, six hundred eighteen".