91000011001 has 4 divisors (see below), whose sum is σ = 91001314404. Its totient is φ = 90998707600.

The previous prime is 91000010963. The next prime is 91000011013. The reversal of 91000011001 is 10011000019.

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 46278335376 + 44721675625 = 215124^2 + 211475^2 .

It is a cyclic number.

It is not a de Polignac number, because 91000011001 - 2¹³ = 91000002809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91000011101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540670 + ... + 688711.

It is an arithmetic number, because the mean of its divisors is an integer number (22750328601).

Almost surely, 2^91000011001 is an apocalyptic number.

It is an amenable number.

91000011001 is a deficient number, since it is larger than the sum of its proper divisors (1303403).

91000011001 is a wasteful number, since it uses less digits than its factorization.

91000011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1303402.

The product of its (nonzero) digits is 9, while the sum is 13.

The spelling of 91000011001 in words is "ninety-one billion, eleven thousand, one".