91100020001 has 4 divisors (see below), whose sum is σ = 91391074692. Its totient is φ = 90808965312.

The previous prime is 91100019991. The next prime is 91100020021. The reversal of 91100020001 is 10002000119.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35863269376 + 55236750625 = 189376^2 + 235025^2 .

It is a cyclic number.

It is not a de Polignac number, because 91100020001 - 2¹⁸ = 91099757857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91100020021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 145526876 + ... + 145527501.

It is an arithmetic number, because the mean of its divisors is an integer number (22847768673).

Almost surely, 2^91100020001 is an apocalyptic number.

It is an amenable number.

91100020001 is a deficient number, since it is larger than the sum of its proper divisors (291054691).

91100020001 is a wasteful number, since it uses less digits than its factorization.

91100020001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291054690.

The product of its (nonzero) digits is 18, while the sum is 14.

The spelling of 91100020001 in words is "ninety-one billion, one hundred million, twenty thousand, one".