109208391 has 16 divisors (see below), whose sum is σ = 154388448. Its totient is φ = 68428800.

The previous prime is 109208387. The next prime is 109208431. The reversal of 109208391 is 193802901.

It is not a de Polignac number, because 109208391 - 2² = 109208387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109208321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66561 + ... + 68181.

It is an arithmetic number, because the mean of its divisors is an integer number (9649278).

Almost surely, 2^109208391 is an apocalyptic number.

109208391 is a deficient number, since it is larger than the sum of its proper divisors (45180057).

109208391 is a wasteful number, since it uses less digits than its factorization.

109208391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2962.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 109208391 is about 10450.2818622274. The cubic root of 109208391 is about 477.9898444415.

The spelling of 109208391 in words is "one hundred nine million, two hundred eight thousand, three hundred ninety-one".