91109667021 has 8 divisors (see below), whose sum is σ = 124762787424. Its totient is φ = 59098162320.

The previous prime is 91109667001. The next prime is 91109667029. The reversal of 91109667021 is 12076690119.

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

It is not a de Polignac number, because 91109667021 - 2²⁷ = 90975449293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91109667029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 410403795 + ... + 410404016.

It is an arithmetic number, because the mean of its divisors is an integer number (15595348428).

Almost surely, 2^91109667021 is an apocalyptic number.

It is an amenable number.

91109667021 is a deficient number, since it is larger than the sum of its proper divisors (33653120403).

91109667021 is a wasteful number, since it uses less digits than its factorization.

91109667021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820807851.

The product of its (nonzero) digits is 40824, while the sum is 42.

The spelling of 91109667021 in words is "ninety-one billion, one hundred nine million, six hundred sixty-seven thousand, twenty-one".