91001000091 has 8 divisors (see below), whose sum is σ = 121505804560. Its totient is φ = 60581764512.

The previous prime is 91001000089. The next prime is 91001000107. The reversal of 91001000091 is 19000010019.

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

It is not a de Polignac number, because 91001000091 - 2¹ = 91001000089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91001000071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21389740 + ... + 21393993.

It is an arithmetic number, because the mean of its divisors is an integer number (15188225570).

Almost surely, 2^91001000091 is an apocalyptic number.

91001000091 is a deficient number, since it is larger than the sum of its proper divisors (30504804469).

91001000091 is a wasteful number, since it uses less digits than its factorization.

91001000091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42784445.

The product of its (nonzero) digits is 81, while the sum is 21.

The spelling of 91001000091 in words is "ninety-one billion, one million, ninety-one", and thus it is an aban number and an uban number.