91011111010001 has 24 divisors (see below), whose sum is σ = 114331507093440. Its totient is φ = 71808209357472.

The previous prime is 91011111009991. The next prime is 91011111010021. The reversal of 91011111010001 is 10001011111019.

It is not a de Polignac number, because 91011111010001 - 2¹⁴ = 91011110993617 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91011111010021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198760991 + ... + 199218356.

It is an arithmetic number, because the mean of its divisors is an integer number (4763812795560).

Almost surely, 2^{91011111010001} is an apocalyptic number.

91011111010001 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

91011111010001 is a deficient number, since it is larger than the sum of its proper divisors (23320396083439).

91011111010001 is a wasteful number, since it uses less digits than its factorization.

91011111010001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397979733 (or 397979726 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 17.

The spelling of 91011111010001 in words is "ninety-one trillion, eleven billion, one hundred eleven million, ten thousand, one".