91000909555 has 16 divisors (see below), whose sum is σ = 116373417984. Its totient is φ = 68153868640.

The previous prime is 91000909511. The next prime is 91000909561. The reversal of 91000909555 is 55590900019.

It is a happy number.

It is not a de Polignac number, because 91000909555 - 2⁷ = 91000909427 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 8412811 + ... + 8423620.

It is an arithmetic number, because the mean of its divisors is an integer number (7273338624).

Almost surely, 2^91000909555 is an apocalyptic number.

91000909555 is a deficient number, since it is larger than the sum of its proper divisors (25372508429).

91000909555 is a wasteful number, since it uses less digits than its factorization.

91000909555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16836506.

The product of its (nonzero) digits is 91125, while the sum is 43.

The spelling of 91000909555 in words is "ninety-one billion, nine hundred nine thousand, five hundred fifty-five".