91010009191 has 4 divisors (see below), whose sum is σ = 94148285400. Its totient is φ = 87871732984.

The previous prime is 91010009173. The next prime is 91010009227. The reversal of 91010009191 is 19190001019.

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

It is a cyclic number.

It is not a de Polignac number, because 91010009191 - 2¹⁵ = 91009976423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91010009171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1569138061 + ... + 1569138118.

It is an arithmetic number, because the mean of its divisors is an integer number (23537071350).

Almost surely, 2^91010009191 is an apocalyptic number.

91010009191 is a deficient number, since it is larger than the sum of its proper divisors (3138276209).

91010009191 is a wasteful number, since it uses less digits than its factorization.

91010009191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3138276208.

The product of its (nonzero) digits is 729, while the sum is 31.

The spelling of 91010009191 in words is "ninety-one billion, ten million, nine thousand, one hundred ninety-one".