91208216516 has 18 divisors (see below), whose sum is σ = 159841784970. Its totient is φ = 45539157952.

The previous prime is 91208216483. The next prime is 91208216551. The reversal of 91208216516 is 61561280219.

It can be written as a sum of positive squares in 3 ways, for example, as 1274204416 + 89934012100 = 35696^2 + 299890^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17177270 + ... + 17182578.

It is an arithmetic number, because the mean of its divisors is an integer number (8880099165).

Almost surely, 2^91208216516 is an apocalyptic number.

It is an amenable number.

91208216516 is a deficient number, since it is larger than the sum of its proper divisors (68633568454).

91208216516 is an frugal number, since it uses more digits than its factorization.

91208216516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11431 (or 6120 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 41.

The spelling of 91208216516 in words is "ninety-one billion, two hundred eight million, two hundred sixteen thousand, five hundred sixteen".