91891565850 has 48 divisors (see below), whose sum is σ = 260446955328. Its totient is φ = 21003786240.

The previous prime is 91891565827. The next prime is 91891565873. The reversal of 91891565850 is 5856519819.

It is an interprime number because it is at equal distance from previous prime (91891565827) and next prime (91891565873).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 43756839 + ... + 43758938.

It is an arithmetic number, because the mean of its divisors is an integer number (5425978236).

Almost surely, 2^91891565850 is an apocalyptic number.

91891565850 is an abundant number, since it is smaller than the sum of its proper divisors (168555389478).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91891565850 is a wasteful number, since it uses less digits than its factorization.

91891565850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87515799 (or 87515794 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 57.

The spelling of 91891565850 in words is "ninety-one billion, eight hundred ninety-one million, five hundred sixty-five thousand, eight hundred fifty".