91721310166604 has 6 divisors (see below), whose sum is σ = 160512292791564. Its totient is φ = 45860655083300.

The previous prime is 91721310166601. The next prime is 91721310166627. The reversal of 91721310166604 is 40666101312719.

It is not an unprimeable number, because it can be changed into a prime (91721310166601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11465163770822 + ... + 11465163770829.

It is an arithmetic number, because the mean of its divisors is an integer number (26752048798594).

Almost surely, 2^{91721310166604} is an apocalyptic number.

It is an amenable number.

91721310166604 is a deficient number, since it is larger than the sum of its proper divisors (68790982624960).

91721310166604 is a wasteful number, since it uses less digits than its factorization.

91721310166604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22930327541655 (or 22930327541653 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 47.

The spelling of 91721310166604 in words is "ninety-one trillion, seven hundred twenty-one billion, three hundred ten million, one hundred sixty-six thousand, six hundred four".