123109191 has 12 divisors (see below), whose sum is σ = 178460880. Its totient is φ = 81779040.

The previous prime is 123109187. The next prime is 123109193. The reversal of 123109191 is 191901321.

It is not a de Polignac number, because 123109191 - 2² = 123109187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123109193) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21811 + ... + 26868.

It is an arithmetic number, because the mean of its divisors is an integer number (14871740).

Almost surely, 2^123109191 is an apocalyptic number.

123109191 is a deficient number, since it is larger than the sum of its proper divisors (55351689).

123109191 is a wasteful number, since it uses less digits than its factorization.

123109191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48966 (or 48963 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 27.

The square root of 123109191 is about 11095.4581248365. The cubic root of 123109191 is about 497.4661017449.

The spelling of 123109191 in words is "one hundred twenty-three million, one hundred nine thousand, one hundred ninety-one".