91000091091 has 32 divisors (see below), whose sum is σ = 149391889920. Its totient is φ = 47981274624.

The previous prime is 91000091069. The next prime is 91000091167. The reversal of 91000091091 is 19019000019.

It is not a de Polignac number, because 91000091091 - 2¹⁰ = 91000090067 is a prime.

91000091091 is a modest number, since divided by 91091 gives 91000 as remainder.

It is not an unprimeable number, because it can be changed into a prime (91000092091) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 648376 + ... + 776138.

It is an arithmetic number, because the mean of its divisors is an integer number (4668496560).

Almost surely, 2^91000091091 is an apocalyptic number.

91000091091 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

91000091091 is a deficient number, since it is larger than the sum of its proper divisors (58391798829).

91000091091 is a wasteful number, since it uses less digits than its factorization.

91000091091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130395.

The product of its (nonzero) digits is 729, while the sum is 30.

The spelling of 91000091091 in words is "ninety-one billion, ninety-one thousand, ninety-one".