91228561208 has 8 divisors (see below), whose sum is σ = 171053552280. Its totient is φ = 45614280600.

The previous prime is 91228561187. The next prime is 91228561217. The reversal of 91228561208 is 80216582219.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5701785068 + ... + 5701785083.

It is an arithmetic number, because the mean of its divisors is an integer number (21381694035).

Almost surely, 2^91228561208 is an apocalyptic number.

It is an amenable number.

91228561208 is a deficient number, since it is larger than the sum of its proper divisors (79824991072).

91228561208 is a wasteful number, since it uses less digits than its factorization.

91228561208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11403570157 (or 11403570153 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 91228561208 in words is "ninety-one billion, two hundred twenty-eight million, five hundred sixty-one thousand, two hundred eight".